Some good basic guidelines for guys and girls alike.
Here they are: “Four Guidelines for Modesty”:
If you have trouble getting into it or out of it, it is probably not modest.
If you have to be careful when you sit down or bend over, it is probably not modest.
If people look at any part of your body before looking at your face, it is probably not modest.
If you can see your most private body parts or an outline of those parts under the fabric, it is probably not modest.
As disciples we are called to be pure and holy. Also to avoid those things which may cause another to sin.
These are some good principles to help us along the way.