Hi, my name is Geoff, and I have Aerolith disease...this is my jokey term for what happens over time when your ONLY study method is solving anagrams. (If you don't know, Aerolith - aerolith.org - is a wonderful website where you race against the clock to unscramble words. It's excellent practice, and I highly recommend it.)
The first symptom of Aerolith disease can be seen when you're playing a game: Let's say it's your turn to start a game, and you have DEIKLMU on your rack. If those letters came up in an anagramming practice session, where you know that there's at least one solution, most experienced anagrammers would find MUDLIKE right away. There aren't very many other ways those letters could combine to make a plausible word, and finding MUDLIKE doesn't require you to know obscure words at all. Easy to solve.
So, returning to the game, you slap down MUDLIKE, happily announce your score of 88 and hit the clock. And...your opponent challenges it off, because it's not a valid Scrabble word. (Kudos to your opponent for knowing it's not good - I wasn't sure until I looked it up just before writing this.)
There's no easy way to fix that problem. The optimal solution for making sure you know MUDLIKE* is no good is to commit all the -LIKE words to memory, and you could do that for similar categories (OUT- words, -LESS words, etc.) - but there are a whole lot of those, so it's going to take you a lot of time, and rote memorizing is easy to get burned out on for most of us. I haven't done anything like that in years, though what I will do now and then - say, a few days before a Nationals - is bring up those lists on my computer screen and read them, speaking the words to myself as I go (or aloud, if I'm alone). This creates at least a dim recent memory of the words. Every little bit helps, right? Having more than one way for your brain to come up with a word is a good thing.
A second symptom is particular to folks who use Aerolith (WordWalls) for all their word practice. There's no penalty for guessing wrong in Word Walls, and so with certain anagrams there's a tendency to type the wrong answer first and then realize, oh yeah, it's not OVERBIND*, it's OVENBIRD or whatever, and then type the right one and move on. In a game, though, every once in a while I'll mistakenly think of my usual wrong guess as being correct. I can usually catch myself before I put the phoney on the board, but if I get careless...
Do understand that none of this is in any way a criticism of Aerolith or other study sites or programs. They're great! I have a case of Aerolith disease myself that could use some fixing, but I've used it a whole lot to study because I find that the format is the most fun for me. And remember what I said when I started the blog: it's better to have an imperfect method you enjoy than a perfect one you don't. Aerolith makes me want to practice words, and that's the most important thing. But when I want to review more in depth or identify holes in my word knowledge like the ones I described above, I'll switch to something like Zyzzyva. Or Xerafin, a new web-based cardboxing app I've been trying out lately.
Or I might try an approach other than anagram solving - could be rote memorizing, could be mnemonics, could be trying to recall words in certain patterns, could be spot-the-phoney quizzing. Any of those methods can help. But I am a firm believer that solving alphagrams is the best way to build a big arsenal of words for yourself, so I'll always spend most of my practice time doing that.