I've done most of my coaching at 9-10 year old group, but spent one season in the 7-8 group first. We only get an 1h or 1h15m for our practices. Dedicating 1:1 time can be difficult so the best thing that can be done is to have multiple coaches running multiple smaller drill groups. It may not provided 1:1 time but it'll be closer with a small group. I told my 9-10 group that there were 6 things that we were always working on improving: hitting, running, fielding, throwing, being a good teammate, and their baseball brain. Told them they can all succeed with the running and good teammate part even if it's their first day on a baseball field. As long as they improve a little in the other 4 then it's a successful season. I'd think that would stick even more so with 7-8 year olds. Good luck!