I like to clean with a LeatherNew spray on a cloth when I can start to see dust on my saddle - every couple of weeks or so. I get a SOFT toothbrush to clean into the tooling (mine's western), and I wipe it down really good. Then I'll use a leather conditioner to keep the leather soft and supple (I like to use the Armorall Gel - it's actually for car leather, but it works great!) I keep it on a saddle stand covered with a towel to keep as much dust off as possible. I oil about twice a year - but beware neatsfoot! It's great for your saddle but is infamous for darkening leather, so don't use it unless you want to darken your saddle. Talk to someone at your local tack shop - they can can help you find something that works! :]
Hope this helped!