So much easier to give pills to unsuspecting & greedy labradors than suspicious & fussy cats!!!
The ways I've managed in the past are:
1. For crushable pills ~ find something super tasty & quite strong tasting that the cat will lick from a saucer. I used fish paste but Pate, meat paste, thick yoghurt or cream can work just as well. Crush the pill between 2 teaspoons (back of one against the front of the other) to a fine powder, mix with paste/pate & let cat lick up. Only use a small amount of paste/pate that the cat will eat in one go.
2. For non-crushable pills (or cats that won't lick up paste/pate) you'll need a human helper (& possibly a thick towel or thick gloves!). Helper holds cat still ~ I find it's better to hold the cat from behind & ensure that claws are managed (wrap in thick towel?). Then pill popper opens the cat's mouth by putting fingers or a finger & thumb in the sides of the cat's mouth & opening it. With the other hand, push pill to back of throat, hold mouth close, & gently rub throat till cat swallows.
The pill-popper things can be invaluable for really difficult & feisty cats.
But cats very quickly learn how to avoid taking a pill, especially if the act of forcing it down the cat's throat is particularly traumatic. So it can help if you can follow up the pill-popping with something the cat really loves, e.g. a good brushing, game with a toy, special food that they don't get any other time. This helps stop the association forming between you (owner) & the cat being grabbed & having a pill forced down it's throat. End on a positive