Sno Seal is the best I ever found. It won't "clog" the leather causing damage like most water proofing products. Best thing is to clean very well with saddle soap and let dry. Heat the leather (I use a hair dryer but can be done carefully in the oven on low heat) and rub in the Sno Seal.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!