It doesn't matter if you came up with it or you learned it from someone else.
One of my favorites is for the hiragana せ I thought it looked like a man with a hat and a big nose looking to the right.
I remembered it by thinking "SEnpai has a big nose."
I also like the mneumonics for tsu ツ and shi シ So (she) is looking up at the TSUn (sun).
by Prince_Wildflower