For rhythm improvement I prefer drumtracks over metronome..
There are so many different types of drumtracks that practising "lock in" is much more effective than with a one-dimensional metronome.
I pick a drumtrack and I will practise loops and riffs and make them up as I go along.
I practise all over the neck switching notes ...to get the diversity...instead of trying to find the closest easiest shortest finger routes.
Sometimes I will pick a simple song and then use the practise session up playing that song in every key possible.
I deliberately challenge myself with all sorts of finger positions.
Sometimes I'll go "Sheehan" and just pick one note over and over for timing.
Playing with a pick is fairly easy......so 90% of my time I practise finger picking without a pick.
Music theory factors in but I don't worry too much about it when I'm playing.........(you can't drive a car down the road while reading the owner's manual at the same time).
There are all kinds of finger/note exercises (and don't forget stretching)........if I run out of those I just make up ones that are difficult to play.
I am always checking my playing style for flaws.
Sometimes I stand in front of a mirror and watch myself play........I often catch myself doing stuff I wasn't aware of.
Then I correct it.
All kinds of ways to practise.
BTW...it doesn't have to be fast to be good...........practising speed playing ALL the time is in my view counterproductive.
Personally I don't spend much time at all trying to sound like someone else (like some famous rock star etc). There are certainly famous riffs that I will noodle with.
I practise "styles" though.