Well, TG doesn't seem to have any qualms about hiring lots more people, as they recently hired I think it was 300 new workers to reopen their flights out of DMK. I'd like to see them put that number of new workers at BKK and do like SQ does and utilize their staff to eliminate bottlenecks and to be on-hand to handle emergency situations. For instance, SQ realized when Suvarnabhumi first opened that passengers were having difficulty finding the right gate. They assigned staff at strategic positions with signs to indicate which way to go for specific SQ flights. In other airports around the world I've always seen lots of extra SQ staff around the departure gates ready to assist passengers, calling out for last call to flights, etc. This extra staff can make an absolutely huge difference in the flying experience. I think one of the major reasons for SQ's high customer satisfaction is the fact that they have this additional staff to handle all these little things that most other airlines, including TG don't do.
Another area is with the busing. I've given up hope that BKK will be able to use air-bridges for all flights, but why not double up the number of buses related personnel so that passengers aren't crowded into the buses? When boarding a plane, the buses often sit parked for 15 minutes or more waiting for the bus to fill up, meanwhile passengers on the bus are breathing noxious fumes and exposed to hot outside air on hot days. Why not have enough buses/drivers so that the bus departs when all the seats are taken and/or after a maximum of 5 minutes?
Open up the arrival lounge. On a recent trip through BKK a TG worker told me that frankly speaking she didn't know why it wasn't open yet. Just that it was some internal TG decision. If they have the personnel, why not open it? If not, hire the personnel and open it soon.
Have one airside business lounge open 24 hours. I can see some pitfalls in this, so it would have to be carefully implemented, but again just with a very small expense of some additional personnel some travelers experience would be greatly enhanced by having a place to relax overnight while they wait for their connecting flight in the morning. Very little cost for TG to make major brownie points with their customers.
Hiring workers in Thailand doesn't cost much as the wages are so low. There are so many things that TG could do just by adding more workers. I've probably only scratched the surface here. But first they need to realize that their level of service doesn't match that of airlines such as SQ and make the decision that they'd like to meet or exceed that level of service. Then study what the other airlines do and make a study of how they can improve their service in those and other areas.