The reason women try on clothes so often is simply because there are no set standards. It's all approximate.
One of the very first jobs I had was in a factory which made women's clothes. Getting each piece the same is basically, impossible.
Added to that, women have an enormous variation in their shapes, especially the bumps, of which there are many.
Then, just to make things a bit more difficult, women have this tendency to be rather fussy about how they look.
As Cindy says, go around some clothing shops.
Be confident though. You are going in to spend your money and give them their income. You don't need to appologise for being there.
If some shop assistant isn't helpful, or gives you any sort of grief, walk out.
Their judgement is nothing. They are there to serve you.
Walk in, say what you want and look at the selection.
One point, try to get some idea of sizes. If they ask your bust size for example, medium isn't quite the answer.
Also, some idea of the sorts of colors you like is a good idea.
