Memes

Be calm, gentle, but firm. No build up, no "I'm sorry kitty, don't be mad" and try not to be tense. Just do it. (If you're tense, they're tense)

Use a treat or food to distract the cat, and hold them firmly (preferably, have a second pair of hands, but I manage just fine on my own)

Proceed with the processes, even if the cat complains, or gets a little feisty (back off if they're ballistic). Let them know (with your body language) that you're not stopping because they're unhappy

Also, make sure they have a good footing. Cats get uneasy if they don't have their feet on something, or if the ground is slippery (like a bathtub)

Put a towel in the bottom of the tub to give them better footing (not the best solution, but it works)