Cheapest option by a long way - booked 7 months in advance. Easy check in and although we had to wait at Istanbul for a couple of hours each way we saved nearly £400 between the two of us Compared to direct flights (where we would have had to go from Heathrow) plane was comfortable and staff were attentive. Flight times reasonable as well. Would use Turkish Airlines again - and they fly to loads of destinations from Istanbul.
Use google flight to assess the cheapest days to travel then book direct- we saved £400 - total cost for two Birmingham to Bangkok and return was £870 compared to nearly £1300 with Emirates for the same dates