When not in use it is important to keep shoe trees inside your shoes for a number of reasons. So long as the fit is good they will maintain the shape of the shoe. Wood trees will help absorb the perspiration which accumulates in the linings during the course of the day. Avoid metal, plastic and highly polished wood shoe trees as they offer no absorbency. Shoe trees also make cleaning and polishing your shoes an easier task.
Trickers and Loake offer their own branded trees which perform excellently and look superb inside your shoes when lined up in your wardrobe like soldiers. These are available from the Bradshaw & Lloyd online store as well as from the Hurstpierpoint shop.