Lspencerini- Listen to "Love in Vain" by the Rolling Stones for an "arpeggiated" version of a very very old blues song not usually played that way.
George-great comments. Crossing to other instruments is also helpful. Subbing in a band practice, I played electric bass for three plus hours on Sunday with some good old southern boys playing loud old time rock- Lynyrd Skynrd, JJ Cale, SRV, CCR, Stones, ZZ Top, Hendrix, Bad Company, Tom Petty, etc. They played dozens of songs I "mostly" knew but didn't know the bass parts for except for a few (Glad I learned "Pride and Joy" this year!!! ). They gave me the key, the basic chord changes and I was on my own.
Besides being incredible fun, it's great training for practicing timing, groove, staying with the song and the band, having to play the song ALL THE WAY through, watching for cues from the guitarists (watching the rhythym player's hands and chords is very helpful) and cues for endings. You can't keep your head buried in your chest looking at your hands.
Also having to listen for intervals on the fly for playing the bass parts is difficult and good training. Especially with all the noise....And best of all, playing with, in this case, a really good drummer!!! Great practice. We even did a jam based on a John Lee Hooker/ZZ Top groove that went on for a long time and was great practice as well as loads of fun. And sounded cool.
They did ask me if I wanted to play guitar on a couple of songs, but I wisely declined......
I still want to learn how to play the ukelele some day, though. Maybe my wife will get me one for my birthday in a couple of months.