Put away items that remind you of the person
It is easier for ladies to do this but in case you have difficulty putting away gift and memorabilia of your ex, then try as much as possible to view it in a positive light. This can be done replacing a romantic emotion with a positive one regarding the items that remind you of your ex. Think of the items as one given by a friend, family or relative. This would help in reducing your emotional attachment to your ex.
Try also to take out time to reminisce about the good and bad times you had with your ex so that you can decide if you truly want to be JUST friends with. If you feel so, then you can try and contact them. Make sure that you do things that will make you happy during this period.