The best way to stretch a leather jacket is to wear it in the rain, do a lot of extreme motions while wearing it and let it dry on your body. Leather stretches easily, and leather jackets must be properly cared for because any marks or changes made on them are permanent.
- Let your leather jacket get slightly wet
Get your jacket slightly wet. The best way to do this is to wear it out in a light rain until the entire jacket is damp. If no rain is in the forecast, spray the jacket with water from a misting bottle. Do not put the jacket in the washing machine to dampen it, as this is likely to cause significant shrinking.
- Wear your leather jacket while it's wet
While the leather jacket is still wet, wear it. Move around in it and do exercises such as push ups, using a punching bag or even just bending your arms repeatedly. This lets the jacket start to stretch and develop attractive wrinkles in just the places where you need the extra room.
- Take proper care of your leather jacket after it dries
Let the jacket dry naturally. Do not put it in the dryer or use a hair dryer on it. Treat it with leather conditioner, and hang it up when not wearing it.