Most foreclosed properties are in a mess because the previous homeowners intentionally left it that way and the banks that own these properties are not going to spend more money cleaning the place up. Your best bet is to advertise your services to everyone or team up with real estate agents and ask to have your company included as a referral to new homeowners of foreclosed properties. Good luck!
Your best bet is to contact the real estate brokers that list the majority of the properties. You will need to offer good service and better rates than others are charging. Simply ask them what services they need and if you do a good job they will keep giving you work. Good luck