With the big kids in my action room who still have handwriting or letter formation goals, one of the activities I set out is a big huge grid on the floor drawn on butcher paper, with my gigantic Sharpies, and offer to make a word search themed about whatever they’re interested in.
The sheer size of the Sharpies is often enough to draw kids in…they’re interested enough to practice writing a letter or two. Or I’ll have them tell me words to write on the word search, but then let them fill in the rest of the blank spaces with random letters of the alphabet, since it’s less pressure to write a whole word correctly and only having to write one letter correctly at a time instead.