-leaving notes and videos telling people who love you how much you love them too and how happy you're with the decision of ctb. Also, explain in detail what you want them to do with your stuff.
-Trying to leave your place tidy is important and depending on the method, the cleaner the body, the better.
It's not the same finding somebody in their bathtube full of blood that finding somebody hang on the closet.
-Leaving also notes or videos to the police and authorities so that they can see that no one murdered you. This was your decision.
-Writing all your passwords and info online could help your family to do whatever it is useful with it.
-Try to leave your life in order: no debts, no secrets, no credit cards or bank accounts, nothing.
-If you have a pet, get him/her a house before you ctb.
And that's it I guess. I dunno if it's a perfect suicide but leaving things in order is very important for me.