I think it would depend a lot on what you're doing there. I've thankfully never had to do regular "push in", but we do intervention blocks where every kid in the grade level goes to a different teacher for small group. A few years ago I was sharing a classroom, so it often made more sense for me to see those groups in one of the grade level classrooms where at least the kids were all the same age and working on similar activities.
I had different plastic baskets for each group that kind of looked like this:
https://www.dollartree.com/large-rec...baskets/204685
In each basket I always kept a set of letter/sound cards, a plastic baggie with pencils, a plastic baggie with dry erase markers, and a plastic baggie with sock erasers for the dry erase markers. The rest of the materials would depend on what was needed for that day's lesson.