Try to find clients with similar goals; they do not have to be at the same fitness level (that’s where your expertise comes in), but it helps if they are working towards the same thing (run a 5K, lose weight or just feel better). Do everything you can to increase group camaraderie; encourage introductions, do some partner drills, allow time before and after for people to talk. Discuss payment policy upfront (if you have 4 people and 1 does not show up do all 4 still pay or the 3 split the fee?). Keep the personal in; allow modifications for each individual. Enjoy; it is my favorite type of training!