Accessing Group Fare Concessions

We are a group of around 20 adults planning to travel from India to one of these three sets of countries for tourism purposes during Jan/Feb 2015.

1. Dubai / Abu Dhabi
2. Singapore / Malaysia
3. Honk Kong / Macau

I am trying to find if there are ways to approach airlines directly for a group discounted fare, more like standard tips and tricks which may work, I am not specifically asking for the cheapest fares for a specific trip.

I also had a look at Can a group of people become a travel agent, with the purpose to get access to direct acess to professional travel resources? however that seemed to me as a recurring requirement for multiple travels, which is not our case.

I also had a look at http://www.tourradar.com/ suggested in Are there any tour group comparison websites? however, this site only compares tours without any airfare, while this is useful in our case, what I am asking for is primarily for the airfare.

I had a look at this Group Discounted Airfare, while tips provided there are useful to me, it doesn't answer my question fully . I am trying to find ways experienced flyers would access the best discount that airlines would be able to offer for such a group size.

My primary worry in approaching a local agent is any discount offered by airlines may be eaten away by them. I am looking to learn from experienced travellers any generic / specific advice. We have many members who are not on full time employment and have all the time in the world to find the best suited travel (not only the cheapest) if there is path that we could follow.