RYO (Roll Your Own)
I read this post for inspiration, but ended up using ryo-modal-mode
It is based on modalka-mode and allows for just one command layer that is not preconfigured, so you can add vim-like keys or just use emacs keys without Ctrl key.
On the plus side there are keywords which allow you to use keys only in specific major modes and run functions before or after the key function.
I found the documentation very accessible on github and on the developers blogpost. There he gives examples on how to use Hydra on top of ryo, too.
As a beginner I found this mode easy to setup and configure.