The use of quality wooden shoe trees is the most important thing you can do to maintain a good pair of leather lined shoes.
The absorbent material such as beech wood absorbs perspiration from the lining of the shoe, keeping it from cracking while helping to reduce the creasing of the upper. Using shoe trees on a daily basis will make shoes look and feel better, reduce odour and increase longevity.
Please note if your shoes are a half size you need to round down to the smaller size, so for example if your shoes are a 10.5 you would need to order the size 10 shoe tree.