One trick to working at speed with Lightroom is to know a few essential keyboard shortcuts. But a command that’s essential to one user is something that another person might never require!
Luckily Lightroom’s menus show the keyboard shortcuts so you can memorize those you need most, but here is my suggestion of those most worth learning.
I do not aim to provide a comprehensive list. After all, Lightroom offers shortcuts for almost every activity and life’s too short to bother remembering the more obscure ones.