@CatLord @BowsacNoodle I've heard some people suggest a bathing routine would really help with shedding on cats. While I am sure that is true, I am also sure that would cause a lot of stress for the cat and the owner as well. And bathing too much can dry the skin. So for cat owners I tend to just recommend bath on an as needed basis, ie they get really muddy or stinky or something. Unless your cat is a breed that requires regular bathing, or is already pretty calm with baths.

furminators are an option, I call it the easy but possibly damaging option. While it does work, it also cuts and tugs the coat so it will always 1) be catching fur even when it's not loose (so it looks like it's working great) and 2) creating loose fur that will soon be shedding fur. I don't think the creators anticipated this, and it's not like it's going to kill your animal. It does work, but basically works a little too well.

I suggest a nice brushing with a rubber curry comb. The rubber will gently catch the undercoat. You may be surprised how much fur comes off.

Once done with that, and you want to be done brushing soon, I recommend an Equi-groom for the top layer; it's going to get all the hairs on the top coat that has been loosened by the rubber curry.

If you have a medium/longhair, you may want to first run a greyhound comb to try to work through the thicker coat, because none of those other combs are going to help with knots, tangles, or a coat so thick they can't properly run through it.

However, do not attempt to untangle mats. Mats are painful, and can damage the skin. They should be shaved off.