Review on Nintendo Switch Joy-Con Controller - Black Skull & Co. Skin, CQC and FPS Thumb Grips Set Joystick Cap Analog Stick Cap, 3 Pairs (6pcs) by Christian Bennett

I've used several different grips on joycons and have been disappointed with other brands in the past, I have fairly large hands and can't stand a controller in general but in my experience the joystick in particular needs something like this and I found this brand to be the first to stay in place for as long as you need it. Instead of snapping over the joystick, consider closing the edges slightly, positioning it where it needs to be, and then letting the edges unfold and wrap. It's a little harder than just clipping them on, but it holds them up much better. Highly recommended.