Combs and brushes.

The first tool purchased by Cocker owners is a comb or brush.

The double ended comb (lower left) has wide teeth for thick coats, and fine teeth for the fine hair on ears. This comb, combined with a detangling rake, are all the basic tools needed for many pets. Various manufacturers, $5-8.
The detangling rake (right center) has a razor blade embedded in a protective covering. As it is pulled through matted fur, it cuts through the mats. I used a wet stone to sharpen the blade and reduce pulling of the fur. Some models have multiple blade, but I find they pull too hard and make grooming less comfortable. 4 Paws.
The card block (left top) has hundreds of spring wire teeth. After a thorough combing, the fur is blocked. This removes loose hair and gives the hair that silky, "poofy" look. Care should be used short hair to avoid scratching the skin underneath. Sergeants.
The grooming blade (top right) looks like a saw blade, leather handles. It can be used single handed, as shown, or unsprung to be held in both hands. The serrated edge is used down the dog's back, front to rear, to remove loose hair. Both dogs and cats seem to like their backs scratched with this blade, and you'll like it because there's that much less fur to fall off on the carpet. After a bath it's useful to "rake" excessive water from your pet's back. 4 Paws, $12.

Especially useful for grooming ears, varied-tooth comb can be held loosely in the hand, so it will "turn" rather than pull tangles. On a light combing, the widely spaced teeth "bite", with the other teeth coming into play as tangles are removed. I generally follow up with the double ended comb or with the card block. Wonder Fluff, $6.
Grooming, Spaniel, Dog Grooming, Combs, Brushes