Although there are no guarantees for anything in life, problems with home exchanges are rare. Using a reputable home exchange service is the first step to ensure a good home exchange experience. The families listed have taken the trouble to complete all the information about their home and filled out a profile. They are offering their own home and are likely to have similar concerns to yours.
A reputable home exchange service will provide a messaging system that does not reveal any of your private contact information. When the discussions evolve you should also consider talking a couple times over the phone or via Skype to better know your exchange partners..
Basically, the most important thing to ensure a good home exchange experience is good communication with your future exchange partners. A great experience depends on trust and mutual understanding. Again, talk on the phone or get to know each other through Skype. Ask for references. Sign an informal written agreement with the terms of your exchange, Stay4free offers this facility which is built in your private messaging system. Also consider what is and is not included (use of home computers, car, bicycles, pet or plant care, smoking indoors, etc.). Find your future hosts on social media.
Before you arrange a home exchange it is also a good idea to check with your home insurance company to check what is covered (also check your car insurance if your car is part of the exchange).
Finally, lock away or remove valuables or irreplaceable possessions before the exchange for extra peace of mind.