My layover on the way to Cambodia was at Don Mueang International Airport (only Silk Air flies directly between SIN and REP, and is expensive compared to Air Asia). This is the “other” Bangkok airport, not to be confused with BKK. This is a teeny airport.
You’ll find the standard stuff–food (Western food=Subway, McDonalds, Dairy Queen, Krispy Kreme, Starbucks) as well as some Eastern options (Piri Piri chicken, and a few noodle places I only semi-registered as I’m not a big noodle person). There’s one or two gift shops, and a few other shops, but after the first hour or two it’s just boring as hell (unlike Changi).
I’ll wait to review the Siem Reap International Airport (REP) until after I’ve discussed my Cambodian adventures.