You might remember the meaning of the character 窝 with this easy mnemonic:
There's a nest in the cave (穴) in the shape of a mouth (口). I put a down box (冂) on it so any man (人) that enters (入) the cave cannot easily spot it and destroy it.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.