The Joe Pass thing is fun. I'm no master at it, but I can generally play figured bass lines on my guitar for most jazz standard charts, and then fill in the comping with chords at the same time. If I recall correctly, I basically focused on learning how to pay figured bass lines first....just be able to take any chart and play it as if you were playing bass, but do so with the flesh of your thumb. Get that down first. Then, once you have those patterns internalized, start crafting all the various types of chord voicings (minor 7, major 7, dominant 7, etc) that correspond with the chords that you would ordinarily see on the first beat of a measure, or the first and third beats of a measure (if you have two chords per measure), but craft the chords so that you can play them in bar chord fashion, and on the upbeat (the "and") of the first and third beats of each measure, by plucking them with your fingers. For example, if you are playing Bb minor blues, your figured bass line for the first measure could be Bb, C, C#, D on the sixth fret (beats 1, 2, 3, and 4), first string, but play the Bb while baring the 6th fret with your first first finger, and plucking strings 3, 4, and 5 on the upbeat (and) of the first beat, creating a minor 7th chord. Do this for the IV chord, and I-VI-II-V turn-around and you have it made.