Liabilty insurance is really the only thing you need and that's pretty cheap to get. Million dollar coverage should run you around $200 for the year. Once you have your professional insurance, then you will need to get your clients anyway you can. Keep in mind, the major gyms have restrictions against people, other than those employeeed, training clients at their facilities, but they don;t have any rules against memebers talking to one another. Nor do they set any sort of limits on visitation. Go to your club/s and market yourself the same way you would if you worked there and then figure out where you are going to train these people (i.e. at their home, office, etc.)