Take care not to injure anyone else. Your family, if you have one, will of course be injured by your departure. Above all, make it very clear to members of your family that this is not about them, it is strictly about you. There is nothing so damaging as making your family feel guilt over your actions. Let them know the situation is not about something they did.
Do you have a life insurance policy? Read it carefully. Is there a clause denying benefits in the case of suicide? Make sure there isn’t. Otherwise, be sure it looks either natural or accidental.
Are your affairs in order? Don’t leave family and friends with a mess. This is about an orderly exit. Have cash where they can get to it. It most cases, your bank accounts will be frozen on your death. Have on-line bill pay? Make sure you turn it off. Cancel any regular payments that come out of your bank account as direct pay.
Do you have a will? Power of Attorney?
Burial arrangements? If you can, handle these yourself. Have you considered “Full Body Donation”? Most medical schools or colleges have a program. They even handle the cremation. Most of the time it is free. Once they are called, they take care of everything. There are a couple of organizations that will facilitate finding a program for you. Check under Resources.