When I was 19 I bought my first good quality leather jacket and shortly after that bought myself a new set of motocross boots for the dez.
Up until this time I had never taken care of my dirt bikin' boots, and it showed. I realized after buying my jacket that good leather is an investment, so I asked the guy who made my jacket what he would recommend as far as maintenance was concerned.
I sponge rinse with lukewarm water, followed by a light application of Lexol leather cleaner and ending with another lukewarm water sponge rinse to get rid of any suds.
Once the leather is clean, I apply Lexol leather conditioner and buff in lightly. After a few minutes, I buff out the jacket/boots with a clean cotton cloth till I get a nice sheen.
Been doing this since '85, and though I've gone through a few sets of boots, my jacket still looks pretty darn good.