If you choose some opening or opening variation and try to understand it, take some time and make some serious analysis of the first 10 or 20 opening moves. Pick your candidate move, right from the first, write down why do you think so. Take your time !!! Only then, before submitting your move, verify database, only then start to read some text about the point of your opening. You will be amazed how often you will choose the right move and once you check some annotations about your opening, and reason behind database moves, you will memorize it with ease, and you will do so much good for your OTB. And most important, next time you'll meet that variation you will know what to do and why.
I started to work on that when I realized ; nothing without good and solid opening repertoire, if you want to become anywhere near solid player.
My motivation was Ruy Lopez, I hated that as black. And now I will learn how to defend from nasty Spanish priest