Not one of my most creative posts...but if you're not already doing this, maybe it will help!
My son makes "roots" flashcards and illustrates the English side, with the Latin/Greek on the back. Then we punch a hole and store them on a carabiner (a keychain might work).
Bonus: They're handy to clip on a keychain, purse, or backpack and review in the car.
Bonus #2: Anything involving illustration improves his small motor skills, in my mind, which equates to better handwriting.