Best way to group Korean vocabulary for learning
I have a lot of great tools for learning vocabulary: quizlet, apps on my phone, digital sticky notes on my computer. But I want to come up with a good way of grouping words so that I can learn them more quickly. I was wondering what other Korean learners are doing?

1) Group words by spelling: 나쁘다, 예쁘다, 바쁘다. This would be like learning words that start with dis- or end in -tion.

2) Group words by concept: 문, 창문, 상, 의자. In other words, words that I might use together.

I'm not a big fan of making up cute sayings to remember words, like "yay, she's poo-retty" or something for 예쁘다.

Question

Best way to group Korean vocabulary for learning
I have a lot of great tools for learning vocabulary: quizlet, apps on my phone, digital sticky notes on my computer. But I want to come up with a good way of grouping words so that I can learn them more quickly. I was wondering what other Korean learners are doing?

1) Group words by spelling: 나쁘다, 예쁘다, 바쁘다. This would be like learning words that start with dis- or end in -tion.

2) Group words by concept: 문, 창문, 상, 의자. In other words, words that I might use together.

I'm not a big fan of making up cute sayings to remember words, like "yay, she's poo-retty" or something for 예쁘다.

Answer

You mean something like thematic word-lists? I also find them to be very useful :)
There are two ESL websites from which I am extracting my vocabulary from. How I'm doing this is, I take a word from one of their lists and look it up on the English-Korean dictionary on Naver to get the Korean word. Then, I input the English and the Korean words along with an example sentence (that also comes from Naver) into Anki and go from there.

The two websites mentioned above are:
1) http://www.enchantedlearning.com/wordlist/
2) http://www.myenglishpages.com/site_php_files/vocabulary.php

I'm looking at your profile right now and I noticed that you're at an A1 level right now though. Personally, I wouldn't really suggest using thematic word lists until a more advanced level to "fill in the holes." I made the mistake of cramming in too much vocabulary in the beginning of my studies and that actually paralyzed me when trying to produce speech. Instead, I think that passively absorbing the core vocabulary by reading books for your level and following along on song lyrics might be a better idea. Of course, do what you think will work best for you personally. These are just my two cents :)