The answer is simple - any kind! It could be your birthday, an anniversary, a bar-mitzvah, celebrating a birth.
Create an online celebration page (Fundraise/Celebration) and share it with friends and family.
A good idea is to print on your invitations the following "In lieu of gifts I would prefer a donation to [charity name]. Please donate at [page link]".
You can also post the link to Facebook or share by email.