Making sure that is no cross contamination is extremely important because a little gluten will have a large response. Getting products that are certified gluten free will insure they were not contaminated in a factory that might produce other products with gluten in them. It’s also important that if you do not have a gluten free household that you do not contaminate your gluten free foods. Some advice on this front; make sure that no one double-dips a knife used on bread back into the butter, jam, ect or the gluten from their bread will get into the container, don’t use the same toaster for gluten free bread, and cook all gluten free products (like cookies and muffins) before the gluten ones.
There are also many non-food products that may have gluten in them that should be considered. For instance, the glue on envelops, lip sticks/balms, shampoos, skin lotion, ect. There are also some medications and supplements that use gluten products as an added filler/binding ingredient. You can go to www.celiac.com for some suggestions on safe brands.
These are just some suggestions. For more information on products to watch out for you should consult with a health care professional.