You might remember the meaning of the character 堵 with this easy mnemonic:
The earth (土) is ten (十) inches deep and is stopping up our pipe. One (一) slash (丿) through the earth should clear up the pipe, but let it sit under the sun (日) for a while.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.