It all depends on the clientele you wish to reach.
My target group is women, moms and pre/post natal. I’ve volunteered to speak to moms groups, give them a quick group session. I’ve brought in lunch to ob/gyn clinics to talk to them about myself, my business and what I can offer their patients…and even the staff. I’ve volunteered my time at new parent support groups, nursing support groups and the local hospital to speak to my potential clientele about the importance of exercise and healthy eatting habits for mom and baby. I’ve taught a group class for a local school for the teachers and volunteered at their career day. I’ve gotten clients from each of these events and they don’t take up a lot of my time or require a big investment, besides time. Its more about getting out there in front of my potential client groups.
Most of my clients come through referrals though. I often try to train clients outside every so often where other people can see me and the type of training I offer. Always have business cards ready because you never know where that next client will come from!