Get some forum software (IPB is good https://invisioncommunity.com/solutions/fan-communities/ https://invisioncommunity.com/solutions/fan-communities/ ) then ge

Get some forum software (IPB is good https://invisioncommunity.com/solutions/fan-communities/ https://invisioncommunity.com/solutions/fan-communities/ ) then get your clients on there, advertise get more people etc. Another good way to get clients is to throw up some script on a place like codecanyon, and people will come to you for custom work/customisations, steer them towards your forum too.