Your best gaming mouse is also your best Photoshop mouse.
That is because gaming mice come with many fully configurable buttons and feature an ergonomic form for long sessions, they are precise and have durable build quality.
Remember: good mice and good keyboard boost your productivity more than a faster CPU does. So don't be obsessed on saving money when it comes to the mouse!
When working through series of pictures the right commands on the mouse can easily save you many hours of time!
Currently my favorite mouse for work is the Logitech G700. It's fully customizable and all buttons are placed where I like 'em.
The general approach to assign the mouse with actions:
- understand that this topic is highly individual
- observe your own Photoshop usage closely
- take notes of the actions you perform the most in your workflow
- decide which actions you want to access with a mouse click
- look up the corresponding keyboard shortcuts here or just google them
- configure your mouse , sometimes it's possible to form groups of actions (ie always the same 3 actions for picture tweaking form a cluster, place them on button G8 > G9 > G10)
- create a cheat sheet because things might be hard to memorize in the beginning
> get inspiration from the net! to tune up your workflows
Other tools which might make your Photoshop life easier are:
- a Surface Pro as an affordable alternative to the very expensive Wacom Cintiq
- a must: wacom tablet ($100+) for retouching and painting
- keyboard stickers for professionals (not for me, because I use around 15 shortcuts only)
- a gaming keyboard where you can assign more functions to shortcut keys (not for me either because they look childishly ugly most of the time)
- your tablet > see this older video. I don't have any experience with this
Here's my own cheat sheet from 2008 / Photoshop CS3
(uhm shortcut missing is Ctrl+T to show layer handles)