You might remember the meaning of the character 腔 with this easy mnemonic:
I've gotten so fat, I bet I can fit a moon (月) inside the cavity of my body. You probably need a cave (穴) for me to sleep and work (工) in now because I'm too large for normal beds.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.