first off think about what made you two break up...take some time, and really consider if you (her too) have matured enough in whatever ways, to make the relationship work again.

if yes, great. but one more thing- do not get back together if either one of you has recently gotten out of a serious relationship (or are still in one lol) and definitely don't get back together if there is any "dirty laundry" from the past. Like messy drama involving other people that hasn't yet been resolved. that kind of thing.