Any advice on "Ticklish Spots"?

Hey before i go on IM NOT A SICK OR PERVETED PERSON :) im just doing this out of play and fun anyways my girlfriend and i are very close (like most bf/gf's) and she claims shes extremely ticklish and loves to be tickled any good advice on tickle spots? where it'd be best to tickle her? i know this sounds strange i guess lol but dont take it the wrong way lol, thanks :)