Usually I just do drill with Ava. She tolerates it fairly well if I bribe her with a treat (I use the Gerber Graduates Yogurt Melts so I don't even feel guilty). I give her one treat for every set (15-30 repetitions or so) and two treats when we're all done.
For variety, I decided to try the top-bottom puzzle idea from the card set game and activity ideas list I posted a while back.
I printed a fresh copy of the fronts of my Initial /s/ set. First I cut them out using a paper cutter. Then I chose 15 out of the 30 cards that I thought would divide well into top and bottom halves and cut those in half. (I'll save the other half of the cards for a different game another time.)
I shuffled the half-cards and started setting them out on the table. I separated the tops from the bottoms to make it a little easier this first time. Every time Ava saw a match, she said the word and set the match aside.
She really enjoyed the activity. I thought it was fun, but the actual speech practice was much less intense than our usual therapy session. It sounds terrible to admit that I prefer drill, but speech therapy for motor planning problems needs to be heavy on repetitions. The child cannot automatize motor sequences without actually talking, and talking a lot.
Using a game instead of drill significantly reduced our number of repetitions. Perhaps a compromise would be to do drill for the first 2/3 of a session, and bring a game out at the end of the session for extra motivation when the child is getting fatigued.