Not only use a metronome but become friends with it.
Whether you are a jazz cat rocker. Blues bluegrass!?
The best players you hear really have a command and feel.
Whether you are going through giant steps or a emin vamp using only pentatonic set it in the 60s or 70s play quarter notes. Only stay in the first five frets. Then 5 to ten etc. then on one string!
Play one note on each beat and try to make click disappear.
Ply behind. On top etc.
Think about how loud or soft you are picking. Of course a drum machine is great fun to work on these skills.
In my experience, guitar players avoid these things.
This applies to the guy looking for a better gig to the guy that wants to sound solid bye the campfire in front of friends and family.