I'm not very big on taking courses myself, as it is scouring the internet and trying to make sense of things myself that have given me the biggest 'eureka!'-moments. Not to say that courses are totally without merit. Far from it! But if you know what you want I would sooner suggest looking into it yourself as opposed to going to a course where they supposedly teach you 'everything you need to know'.

This particular source sprung to mind when I read of your problem, I suggest you read it through. It's a chapter from a book on how best to practice your technique on piano. It focuses on the best way to memorize musical scores, but I think the general techniques can be succesfully applied in many different situations. The link below brings you to the first paragraph of the section I'm talking about.

http://www.pianofundamentals.com/book/en/1.III.6.1

The general ideas posed are

1. memorize things in different ways, memorize them verbally, in writing, if applicable in actions or in different sequences. By remembering them in different ways you can always fall back on a different kind of memory if a particular one fails.

2. Don't be afraid to forget. If anything, try and forget things once you've learned them, and then relearn them. things that are memorized more times over tend to stick with you better then things you've only memorized once. So once you've learned something, try and forget it. If you can't succeed in forgetting it, then it probably sticks well enough to not be forgotten for quite a while.

of course, there are probably a lot more little tricks to memorizing as best as possible. like many things, just practicing it frequently probably helps a lot as well. Keep searching and good luck!