The most effortless way to play online poker is to use the keyboard. It's way superior to mouse/voice.
When I used to play poker a lot (years ago), I used an AutoHotkey script in order to control everything I wanted, regardless of the integrated hotkey features in the poker client. I rarely touched the mouse. Nowadays, I am very far from playing as much as back then, so I don't have an autohotkey setup. When I find the time and motivation, I am going to recover my old setup, even if I am not going to play that much again, just because of how superior it was to the mouse.
If you prefer to stick to the mouse, make sure your mouse is ergonomic enough. My old mouse was causing me troubles, because it was too fat at the back. Also make sure your hand is well supported. Most of the weight should be rested on a flat surface. Don't rest it on the edge of the table or anything else too pointy.
If you ever feel you are making too much damage to your hand, and you start to wonder about RSI or CTS—DON'T PANIC! Most of that is just psychosomatic. I used to destroy my hand for hours, and I still do it sometimes. At one point I began to worry about any possible long term effects. This worry only worsened my condition. I had no idea how much physical pain your subconscious can induce, just to prevent you from doing something YOU THINK IS BAD for your health... until I stumbled upon some article on the internet. I probably have the link to it somewhere in my old bookmarks, but I just googled and
found this site. It sounds very familiar. Perhaps it's the same article. It's worth reading anyway.