I think we should make an effort to develop our own styles, so that the end result fits what each of us individually thinks something should look like.
There are a number of ways you could approach this, including dark-to-light and light-to-dark.
My general method would be to undercoat in the midtone colour, applying at least two coats for full coverage.
Then shade it (usually for a brown like this I'd just add black, but darker blues mixed into the midtone can work nicely too) with glazes, then modestly highlight it - since I go for a realistic sheen on leather I don't overdo the highlights because gloss + strong highlights tends to look wrong. For the highlights a flesh colour often works nicely, which I presume you'll have at least one of.
After that's done, then I apply a thin glossy coat. Acrylic medium or Future/Klear are both good for this and widely available.
When the finish is dry (for Future it's a good idea to let it cure till the next day ideally, although you can work on it within five minutes if you had to!) I'll then add light wear around buckles and other areas that might receive it, concentrating on the edges. Less if more here. Tan/orangey colours and even certain fleshtones are used for this, basically something the colour of untreated leather.
When developing your painting methods working from photos of the real thing is a good idea so as not to go into the realm of fantasy, although you can of course exaggerate things for effect if that suits you.
Einion
