The best tool is a metal comb,  the one with wide teeth helps remove knots, and the closer teeth maintain the coat.
A brush just glides over knots.  If you cannot see the skin when parting the hair there is matting there.

Brushing depends on the length of coat, once the hair gets to 1cm and longer it needs to start being combed daily. Longer parts such as the ears and tail should always be combed.
The best way to comb a dog is to start near the base of the tail pushing the hair towards to head and combing one piece at a time.

I do not dematt hair that it severly matted as it causes paina nd stress for your pet.

The best way to prevent matting is to always comb you dog after getting wet and have a tidy up between grooms as the groomer can brush your dog properly and bath it without it matting.

If you have any questions, don’t be afraid to ask, I am here to help you keep your pet knot free and comfortable.

Here is my blog post with information about how to brush your dog properly between grooms