Hi,
In the normal course, you could leave them alone and they will get settled once you complete puberty. However, if you are very much worried, or if you feel pain in the area, you could talk to your doctor and get his advice.
Solace
I'm not sure I understand what you're referring to. Do you mean large nipples or nipples enlarged because the chest is also enlarged?
Many factors can enlarge the chest and nipples, such as when you gain weight or consume steroid to pump your muscles. If this is the problem, then it's simple, start working out and throw away your steroid.
If it's not the problem, then you might just happen to have naturally large nipples, which is perfectly normal, and there's nothing you can do about it. Besides, some women (and men) -- depends on what your orientation is, do like large nipples. Don't worry!