Hi Sheri, Thanks for asking...
My favorite strategy is to memorize a piece backwards!
What I mean is start with the ending measure or ending 2 measures and memorize that little part first. Then when you have that done, add a measure preceding that chunk and learn that phrase together to the end. Little by little keep adding a measure at a time till you can play the whole piece through to the end.
The problem with memorizing is that most people start at the beginning and so that part gets practiced A LOT and is really familiar but the ending is really hard to remember. But if you memorize backwards, then you get to know the piece more evenly (and in my opinion more thoroughly).
A side benefit of this method is that you are more able to pick up the musical line if your mind goes blank while performing. You just skip to the next phrase and then carry on to the end where you can finish strong since you know the ending so well! No kidding, my daughter who has Down syndrome memorizes her recital pieces this way, and at a talent show this spring she got very stuck, but she calmly kind of wandered around that key till she got her bearings and finished fine. I was prouder of her for having the presence of mind to persevere and keep going calmly and ending well than if she had done it perfectly the first time!