You love the look and feel of your leather coat, but there's one problem: It squeaks when you move. Understanding why it makes so much racket is the key to reducing the problem. Leather squeaks when it rubs against itself. The newer, shinier and stiffer the leather, the greater the squeak. The long-term solution is to break in your coat so that the leather is supple and squeak-resistant. In the short-term, there are things you can do to move the process along.
Sprinkle talcum powder into the seams of the coat. Apply it liberally. The seams are where leather meets leather and are the biggest source of squeaks. The talcum will lubricate the seams.
Work the talcum into the seams by gently massaging and flexing the leather around them. Go gently; you want to stretch the seams, not pull them apart.
Wipe off the excess talcum powder with a static dusting cloth.
Put your leather coat in a clothes dryer with a few tennis balls. The tennis balls will "punch" the coat as they tumble together. They'll also absorb loose talcum powder.
Set the dryer to tumble only. Do not use heat.
Start the dryer and let it tumble. The longer you run the dryer, the more the leather will get flexed and stretched.
Purchase a commercial leather conditioner. These products make leather more supple. Ask the retailer where your coat was purchased whether there is a recommended product.
Apply the conditioner to a small patch of the leather in an inconspicuous location, such as the inside of the cuffs, the underside of an epaulette or a fold inside the coat. Follow the manufacturer's instructions for application.
Let the coat sit for 24 hours.
Check the place where you applied the conditioner. If the leather isn't discoloured, apply conditioner to the whole coat.
Use unscented talcum powder, if possible. If you love the smell of leather, you don't want that "baby-fresh" talcum fragrance interfering. If you don't have tennis balls to use in the dryer, try clean shoes wrapped in towels and fastened with rubber bands. For darker leathers, neat's-foot oil is an alternative to conditioners.
Never use heat when tumbling a leather coat in a dryer. Heat can cause the leather to shrink, destroying the coat. Use caution when testing conditioning products on lighter-coloured leathers, as they are more prone to staining.