Here are some tips for avoiding rip-offs: Red flags should go up the minute someone rings your doorbell. If you didn't invite someone concerning roofing, painting, paving, etc., don't even listen to the person on your doorstep. Ditch the pitch by closing the door, especially when high-pressure or scare tactics are employed. Particularly alarming is a demand for cash payment, which means no written contract will be offered. Watch for new vehicles with out-of-state plates and a toll-free number instead of a local telephone number and address. Scam artists work in pairs, too. While one distracts you, the other robs you. Contracting for home repairs requires common sense.