I get these two words mixed up:

Inevitable     =unable to be stopped. Here’s a way to maybe remember this. EVIdence show that this is definitely                        going to happen thus inEVItable

Inedible        =unsuitable to be eaten. The base word inETItable which can be eaten but un means it can’t. Both                          share EDI.

Do you have a better suggestion on keeping these separate? If so, please share.