You can waterproof and protect your leather garment by feeding it with mink oil or silicone spray. However, the process will most likely darken your leather. So its a good idea to test it first on a tiny area on the inside seam. If you are caught in a shower with an untreated leather garment, allow your leather garment to dry on a flat surface away from heat. Leather should dry at room temperature overnight. Remember, the radiator is no place to dry leather -- excess heat saps up the leather's essential oils and can leave it hard and cracked. If your leather garment gets wet, hang it on a wooden or padded hanger away from heat to dry.
When you first purchase your leather garment, put it on a shaped or padded hanger and store it in a cool dry place. Give it plenty of room -- it will wrinkle if crowded. And, of course, don't let it come into prolonged contact with plastic or moth balls.
If you need to remove wrinkles from your leather garment, you may do the following, but take great care. To remove wrinkles you may use an iron but do NOT put iron directly in contact with leather. Use a 100% COTTON cloth or brown paper bag in between the leather garment and the iron. Gently press over with mid-low heat and do not leave the iron on the garment for long period. Always use extreme caution and patience.