I've tried to follow a plan in keyboard command design where keyboard commands have some kind of logic in them. Lower case letters are for commonly used commands and upper case letters for less used, but also some letters have similar kind of action with lower and upper case forms. This is done in some roguelike games, but I think it could be extended as much as possible.
For example I had 'q' to quaff as usual, but previously I also had it search for water sources from the environment first and if they were skipped then drink something from the inventory. However I started to think it was confusing and added a new command to drink from environmental sources with 'Q'. Even that command is often 'quit' in roguelike games it doesn't take a long time to adjust to that. There are also some other keyboard combinations in the same key with lower case for items and upper case for environmental sources. It's a nice, logical arrangement and easy to remember.
It's not particularly useful trying to cut down the amount of keyboard commands, because you still need some kind of way to activate commands. Menus can be ok in some situations, but worse in others. The design of keyboard commands actually takes some consideration that I believe developers of older roguelikes never did. That was the case with many other areas of design as well.