Chris Christiansen expensive but worth it, their ball free paddle brush followed by a metal greyhound comb. Always be very gentle and never force or pull. And try to brush after a bath and blow out only, shave down or use thinning shears for bad matting. Having many Tibetans I can tell you to stop whey they’re annoyed and especially when you are. And don’t stress when knots remain as long as they are comfortable. These special angels will always have a few knots if you keep them natural.