A couple of important points to note:
1 - Culture & threshold for compliments
Thai culture compared to Western culture means that people are much more willing / likely to give a compliment to strangers. So back in the west, unless it's some cat calling US construction worker, it's very unlikely anyone would give a compliment to a stranger, but in Thailand it seems the norm, especially with Farang. My son, who is 9 and half Thai, has had random strangers tell him that he's handsome etc in 7/11 or at the traffic lights since he was about 4 or 5. With compliments being more the norm, it means that there's a lower standard required to illicit a comment compared to in the west (e.g. They'll compliment anyone who's decent looking, not just models).
2 - Different standards of Beauty
Within Thailand having a bridge on your nose and white / pale skin are considered very desirable features. Comparatively no one really cares about either that much in the west because the majority of Caucasians have the same look. So assuming you're Caucasian, you're already ahead of the curve and will be seen as handsome provided you're not overweight (If overweight, they'll call you cute instead lol) or wearing a nasty scowl across your face, then you'll probably be called handsome as a compliment, doesn't mean they're interested in jumping you though.