“2 D’s, 2 S’s and three emotions” goes the old mnemonic, I think.
Someone suggested “S S D D G H B”
My latest ideas are:
Three emotions (GHB), two innocent reflexes (SS), and two sinister sounding verbs (DD).
Grumpy, Happy, and Bashful are emotions, sleeping and sneezing are innocent reflexes, and to doctor something or dope it sounds sinister like cheating in horse racing.
You can also make it into a three line verse with three syllables per line and the three syllable title: Seven Dwarfs. The first and last lines rhyme.