In this video you will see what I find to be the cheapest, easiest and most efficient way to clean leather wether it's in your car, your sofa or a jacket, most of the leathers can be cleaned this way.
All you need is some vegetable soap, a couple of soft cloths, a bit of water and a small brush.
If you have this stuff at home, you can clean your leathers for free !
Do not use chemical soaps ! Vegetable soaps such as Marseille soap will not harm your leather as they don't dry it out. If it's natural and good for your skin, it will be good for leather.