How can I find cheap first class flights?

This question is very broad, but it boils down to four possibilities:

• stumble across an "error fare" or the like - there are newsletters, twitter feeds, and old-style forums dedicated to these. You will have no control over the route or timing but could have a wonderful time anyway
• Buy an upgrade from a regular-priced seat. This will be a lot cheaper than buying a ticket guaranteed to be up-front, but of course you don't know when this will be offered to you.
• Join a loyalty program and save up enough miles to redeem for a "free" seat up front. These days most programs charge fees for their free seats, but it will still be cheap (until you think about all the times you paid $50 or $200 more for the seat that earned miles). Time was, a business or first seat only cost about 20% more points than an economy one. This requires a LOT of research into FF programs but gives you full control over when and where you fly up front
• Join a loyalty program and get upgrade certificates, which you may be able to use once in a while, to get yourself up front.

None of these are quick and easy. You can make this your hobby, and find plenty of company on the internet to do so. It used to be one of my hobbies but the continued devaluation of FF programs meant that I was better off investing my time in billable work and using the resulting money to buy plane tickets directly. Your mileage may, of course, vary, especially if an employer or client is buying you a lot of economy tickets anyway.

There are many different levels of "premium" classes.

• The most basic is that you get a glass of sparkling wine and a meal while the people in coach don't, but the seating is exactly the same. Some airlines used to just have a (movable) curtain separating the two classes, and this was mocked in this ad
• The next higher level is that they block the middle seat in each row of 3, so you have some extra elbow room. Example
• Then, the same thing, but the elbow rests are moved a bit so you have a bit more space at waist level.
• Then, you get actually larger seats (e.g. 2 seats where they would usually have 3). This is measured in width and "pitch" (the distance between two rows). Example
• Then, they increase how much the seats can recline
• Then, you get to the point the seat reclines to fully flat, but not horizontal Example, see business class
• Then fully flat and horizontal
• Then size/space increases
• Until you get to a fully enclosed "suite" with a bed.

There are also differences in equipment, mostly the IFE (in-flight entertainment) which can vary from shared overhead screens to 20"+ personal screens with hundreds of movies and shows at your disposal, as well as catering.

So, most definitely, your experience may vary a lot. It depends on the airline, class (premium economy, business, first, suites...), short-haul v. long-haul (note that for some airlines, "regional" can cover flights of 6+ hours but still offer the low-end product), the aircraft type, the generation of the aircraft (they don't refurbish/upgrade all aircraft overnight when they introduce a better product), and more.

"Premium economy" on some flights may be better than "First" on others (by far).

Some airlines use different names for different products, or qualify them (with "regional" or "domestic/international" or "short haul/long haul" or "Euro/World"), some will just say "First" or "Business" for any flight even if First on one flight is completely different from First on another.

You can have an idea of the type of comfort you'll get by looking at sites such as seatguru.com which will show you a map of the cabin and give you details (such as width, pitch, type of seat, reclining angle, equipment, etc.). You'll notice that many airlines have different products, and even the same type of aircraft (e.g. 777) can have many different variants. You can look up what type of aircraft will fly which route, but it can be tricky to know which variant exactly in some cases. And of course there's the issue of the last minute aircraft switch.

The best experience IMHO is long-haul first class on South-East-Asian carriers such as Singapore Airlines or Cathay Pacific. Some Middle-East carriers are also supposed to have very good products but I've never experienced them.

On the better airlines, even long-haul business class is just a significantly better experience. But still not cheap, we're usually talking a few thousand $/€/£.

Of course on some flights/airlines you can get the lowest end of premium classes for not much more than economy, but it will rarely be an "experience". It'll be a bit better, but often not worth the extra cost (in many cases people take that for the flexibility of the fares rather than the better product).

If you really want to enjoy a real nice premium airline product, you'll usually won't be able to get that for less than a few thousand $/€/£ if paying.

If you travel a lot (especially for work), make sure you are a member of all the relevant loyalty programmes, and try to concentrate your travel on a single one. If you spend a lot, make sure you use credit cards which give you miles. I used to be able to run a lot of business expenses on credit cards which gave me miles and that allowed me to travel in business or first quite a bit.

But this needs significant expenditure, long-haul business or first class flights often require a lot of miles/points (and it seems that constantly increases), and availability is often limited (and now many airlines have several levels of awards: the cheaper ones use less miles but you can only find a seat once in a blue moon, the more expensive ones let you book any available seat but will use sooooo many miles.

You can also use miles to do upgrades, though again, this often becomes more and more difficult: some airlines will let you upgrade from coach to premium coach or premium coach to business or business to first, but not necessarily skip from coach to business or first, and the process can be complex.

There are lots of sites out there which talk about miles and points and free upgrades, you can spend hours (or even days) reading all that, but there's no magic bullet. Airlines reward their better customers, they have no reason to give out seats in premium classes cheaply.

Are there any rules of thumb to find these?

No. It typically requires a significant search effort. There are websites that specifically help with this type of thing. Some are free, some are not. A good starting point is https://www.flyertalk.com/forum/premium-fare-deals-740/

Flight prices have little rhyme or reason and can vary massively with even small changes in the itinerary.

Are there routes where this is more likely to happen?

Yes, but the rules are complicated. So-called 5th freedom routes are good candidates. See for example: https://thepointsguy.com/guide/north-american-fifth-freedom-routes-points/

Some regions and airports tend to be cheaper than others. Early this year there were good deals out of Bangkok. At the moment you can get BKK<->HKG on Emirates First for $900 US roundtrip. Direction matters, HKG<->BKK would be $1400 instead. So consider adding repositioning flights.

How can I find out if this will be a good experience or if rather the company is selling a glorified economy sit?

Research the Airlines and the specific planes before you book. seatguru.com is a good starting point but there are tons of online reviews for pretty much any airline and aircraft type. Many Asian and Middle East carriers tend to have a very nice first class. The only US carrier left with an international first class is American Airlines. European carriers are mixed. I would also consider Qatar Q-suite. While this is technically a business class, the in-flight experience is "first-class" like IMO.

A big part of the experience are also the first class lounges (which are also reviewed on YouTube all the time). In order to get the full experience here, you need to fly to/from/through a hub airport and make sure your itinerary has enough time for this.

One more tip: consider buying or upgrading with travel points from reward programs (like Credit Cards). This may be a way to get your hands on a ticket with a high cash price.

Why not talk to a travel agent in a physical office.

Walk in to a travel agency, be nice, strike up a conversation and let them know what you want.

Travel agents are regularly "offered" travel and hotel tickets at discounted rates. Perhaps one day, if it is allowable for them to do so (many of these tickets can be passed on to their clients), they might offer you one of these tickets at a reasonable price.

I think your best chance is smart usage of miles and points. If you accumulate them wisely over time, and use them wisely, you can get great value.

1. I'd start with blogs. There are many miles&points blogs, my favorites are Live and Let's Fly and One Mile at a Time. They have lots of content about how to accumulate and use points (they're very US-centric though), and tons of reviews that let you know exactly what to expect.

2. Accumulate miles - try to concentrate your flights on carriers that let you use the same frequent flyer club (you can, with limitations, fly with airline A and get miles with B). The easiest way is to stick to one of the 3 global alliances.

3. Accumulate credit card points - this is a big thing in the US, less in Europe. By strategically applying for credit cards and spending on the right card you can accumulate points, which can later be converted to airline miles.

4. Stay updated - read blogs and news, occasionally do flight searches, set price alerts, so that when a great chance to redeem miles for first class pops up, you'd know.

5. Be flexible - If you start by choosing time and destination, and then look for the best flight, you're unlikely to find great catches. But if you start by finding the perfect flight and plan around it, chances are better. Suppose you find a great opportunity for 1st class from Zurich to Los Angeles. Maybe you live in Paris, and never intended to visit LA, but it shouldn't stop you.

6. Be spontaneous - Sometimes the best deals show up the last moment. If you're ready to grab it, your chances of getting a deal are better.