I’ll share my technique

1. Control the back of the head with your off hand. At first by gripping a handful of the scruff of their neck, later just by cupping the back of their head once they’re used to it
2. With your main hand, get a little slippery on your index and thumb and grip the pill between them
3. Put your main hand palm up under their jaw and tip their head back with it.
4. Use your middle finger to press on the side of the mouth, near the corner. Their mouth will open.
5. Your thumb and index should be in position to flip into their mouth with a twist of the wrist while keeping that middle finger in place.
6. Squirt the pill from your slippery fingers with a pinching action. This will shoot the pill back into their throat if executed well.
7. Use your palm to close their mouth, keeping their head tilted back until they swallow.

This should all be done in a pretty smooth quick motion. Cats can understand some human language if you talk to them regularly, so I talk them through what I’m doing each time. If they spit it out, I just pick it up and repeat while telling them they have to swallow. My cats are all used to it now and take their pills without incident.