How do I ensure that border agents stamp my passport neatly, without wasting space, ruining blank pages, etc? [duplicate]

I travel a lot within Asia, and the Immigration officers of some countries are more diligent than others in finding empty spots in already used pages, rather than stamping a new page (China is probably the best country for that, Immigration officers are really cool about this part, at least). On the other hand, some countries are the worst offenders (and, incidentally, the US comes to mind...).

In a few countries, especially Thailand and Korea, Immigration officers have a nasty habit to stamp entry stamps systematically on new pages. I have resorted now to two strategies. In countries like Korea, where I can actually see my passport at all times, I tell them on which page to stamp. I usually put a small yellow PostIt marker to help them. I even had to grab the hand of a Korean Immigration officer twice, preventing them to stamp on a blank page, after leafing through my half-stamped pages, and looking for the next available blank page.

In countries where I can't see what's happening to my passport, like Thailand, I still resort to the same request, backed up by the yellow marker, but also cover the blank pages with full-page PostIt stickers bearing the word NO. In some places it works, even making the officers laugh, in some others, not so much. Thai Immigration officers are usually cold, sometimes all the way up to aggressive, and this strategy has not always been well-received. Verbal requests are ignored (as in "do not talk to me"), and I found a couple of times a full-page PostIt ripped off and the stamp on a blank page, despite everything. So your mileage may vary, depending on countries.

But the bottom line, if you put a marker in your passport and ask politely, you'll have a lot of success.

I would just ask them to stamp on a specific page, and possibly at a specific point on that page.

Worked wonders for me with the Russians - I asked them (I learned how to do it in Russian, as those officers usually don't speak English) to stamp the visa rather than the facing page.

When I did this on exit, they suggested putting the stamp on the machine-readable stripe, but I asked them to stamp right next to the entry stamp instead, and they did.

Equally, I got the Americans (at Dallas airport) to stamp the last space of my first stamp page, in a vertical manner, rather than the next page.