I am also a very thin boy. I'll give you some advice on dressing. For a thin boy like us, we can't wear a straight suit, because our shoulders are too small to hold, so we can't highlight the effect of the suit. So I recommend wearing a Korean slim suit, which looks more energetic and handsome. You can choose plaid shirts, contrast fashion T-shirts, and match Korean slim suits. For pants, choose casual jeans, choose plate or straight tube. Paired with a pair of skateboarding shoes and white canvas, it will look very sunny in short.