One of the many things we are working on is improving Ruby's ability to pick up things with her pointer finger and thumb. When she's shoveling in finger foods eating, she still tends to 'rake', using her other fingers. Sometimes she uses the pointer and middle finger, but her palm is always involved.
We've tried to give her one puff at a time with varying success. Oh my, how time consuming is that! We still do this sometimes, but whenever we give her something on her tray, she reverts to the rake.
We then tried taping her fingers. She did ok with the tape, but because of the whole-fist approach she takes to eating, the tape was soaking wet after just a minute. That made tape-removal very difficult; taping was a one-time thing.
For now we have landed on the socks. I put two small holes in the feet of old Ruby socks for her thumb and pointer fingers. Then we put puffs or other finger foods on her tray and she has some practice using the pincer grab. The socks do get quite dirty, requiring washing after almost every use, and it's not perfect because she still can push against her palm a little, but for now, it's our best option.