There are a few key things to remember if you want to care for footwear properly
Remove insoles and the laces too if they are very dirty.
Outside: Brush off any dirt every time you’ve worn the footwear. If the dirt is hard to remove, rinse the footwear under running water. Special leather cleaners should be applied if nothing else helps. Soap damages the impregnation and most types of leather.
Inside: Leather and textile linings (as in most GORE-TEX®boots) are best cleaned with a sponge or a soft brush and fresh water. Do not use hot water.
Drying: Thoroughly dry your boots after cleaning in a well-aired, dry and shady place with their tongues wide open. If really wet, stuff leather-lined footwear with newspaper and exchange the newspaper several times. The same applies to GORE-TEX ®boots which dry faster and more effectively with paper.
Please note: Never keep wet or damp shoes in non-aired and humid places like plastic bags, car boots, basements etc. Never dry boots near an oven or over fire or any other source of heat. The leather will burn, turn brittle, dry and crack. Another downside is that the entire shoe can lose its shape.
Regularly apply impregnation sprays (also on new footwear). Spray on the dry footwear after cleaning. The impregnation achieves its full effect after 24 hours. Spray carefully and keep about 30 cm distance. Don’t forget the shoelaces and the inaccessible corners on the tongue.
3. Leather care
Dry leather needs moisturizing. Use special wax (no grease or oil). Massage a thin coat of wax into the dry leather. Please note: With each wax application, the rough surface of nubuck, suede or any other split leather will darken slightly. If you don't this effect you can roughen up the leather again with a special suede brush. Brush off any excess wax.
4. Further Tips
Only store your boots upright with no pressure in a dry and well-aired place. Tip: Use a shoetree.
Don’t let your footwear come into contact with oil, diesel, petroleum or slurry. If this happens clean your footwear immediately.
After a longer period of storage, roughen the tread on the sole a little bit, using a wire brush or fine sandpaper.
Brush off your boots every time you've worn them.