Something that has helped me when learning a new language
In addition to learning Korean, I started learning Japanese (again). I say again because I attempted it a few years ago and failed miserably.
However, after having a good enough time with Korean (not to imply I'm at a good level), I realized I prefer learning in a certain way.
One thing that has really helped me is creating sentences with the grammar that I know.
Now, that may sound obvious to some. Yeah, no shit you'd want to actually use what you've learned. I'm a capital-D doofus, however.
I wanted to do something different, though. When I started learning Korean, I would, after each lesson, create simple sentences using the grammar point I learned. The sentences I would create would be very simple (like "사과를 먹어요" or "I eat apples"). Very basic stuff.
But, I would then add onto that with the following lesson. Say I learn how to use adjectives to modify nouns. I would write a sentence describing those apples I eat, for example (맛있는 사과를 먹어요 or I eat delicious apples). In other words, I would build upon what I know. This would force me to use past lessons and mix it up with current ones (and just mixing things in general). This would then help me to not completely forget what I've learned.
Before, when learning Japanese, I wouldn't do this. I just thought that my absolutely m a s s i v e brain would just absorb the information and I'd be good to go. That didn't work.
So, anyway. Now I'm doing that with Japanese. Making simple sentences then adding onto them and more creating complex sentences. And you know what, I'm having a much better experience this time around. I'm still very much a beginner (in both languages), but I feel more confident in my ability to stick with them.
Here's hoping.
Kanji is still kicking my ass, though.