You might remember the meaning of the character 诸 with this easy mnemonic:
All the speeches (讠) that I heard today were ten (十) minutes long, and one (一) person even talked about how the earth (土) will one day be slashed (丿) in half by the red hot sun (日) rays.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.