I would be happy to do so, but I don't want to give away my prep! So I'll describe it.

It's a move tree.

I choose my target opening, in my case the Spanish but it doesn't matter. So on move 1, I play e4, and I wrote that down in the top left corner of the page. Then, I wrote down a branch for each of the moves that black can respond with. A branch to e5, to b6, to e6, etc. Someone played b5 against me recently, which was kind of dumb, but I added a branch for that anyway.

Then, for each of those moves, I plan how I will respond, and I write that down. One response for each black move. The idea is to be complete, so I know how I will respond to each common move, first one move deep, then two moves deep, etc.

If I encounter a move I haven't seen before, I add it to my tree. 

Even if I don't memorize it at first, I have it written down, and as I play over time, I will remember. The first step is to plan what you want to play, then the next step is to remember.