My friend has brown eyes so she use gold eyeshadow and it looks great - also for going out or a party, try a gold barry m dazzle dust (if you are american don't know if you can get it there soz)
Pretty, springtime eyes can be created using some of the pastel, eye shadow colors - pale pink maybe?
Definitely try the smokey eye look and experiment with lots of different colors.
also wear a big volume mascara to draw attention to the eyes or try rimmel london sexy curves mascara
hope this helps :)Makeup Advice for brown eyes?
Purple eyeshadows really help to bring out brown eyes. Since your 15 a shimmer purple should work fantastic. You can find beautiful colors in the Loreal HIP line at WalMart, Target, etc. Covergirl also has a few great purple shades. Give it a try! Have fun!!