I had a very good shoemaker/ boot repair guy tell me to not use saddle soap and leather conditioner on riding boots. He said the best way to take care of them is to wipe off any dirt/mud with a damp rag. Then use regular shoe polish.
I can't say I adhere to this all the time - often clean with whatever i'm using on my other tack. But they do come out nice when I use his method.