This are my principles for layout:
I am using Callum style layout. Here you can read explanation by Callum himself and his reasoning for not using mod-tap: here
There should be only one way to type key. Key can be on different layer but it must maintain its physical location.
The less features are used the better.
trilayer is cool.
There is 🐍 key for no reason.
As well I have added one shot layers compatible with Callum's one shot keys.
There is simple TMUX layer as well.