Can you give examples of some basic or generally accepted lines for walking bass over this particular change (ie. the Autumn Leaves changes)?
Feel free to illustrate in scale numbers or names over something like f#dim - B7 - Emin.
This assumes II-V-I is the sequence.Although it'll still work with IIo - V - I as the intervals are m3 and b5 as opposed to m3/maj3 and p5.
A simple common one is R 2 b3 3 on each bar. This brings the 4th beat in each bar to the leading note of the next bar.
Another is the opposite way.R b7 6 5, bringing the last beat in each bar to the note above the next root.
Another is to arpeggiate by using 1 3 5 b7 on each bar, although this isn't exactly what some would call a walking bass, even if it's playing on each beat.
Next uses two quavers followed by 3 crotchets. R 5 3 4 b5. The b5 leads to R of the next bar. It is a strange concept, but works well.The 'leading note' creates tension by a semitone away from the target note - from above rather than the usual below.
Next, there's a chromatic run which goes 1 #1 2 #2 3 (1 b2 2 b3 3 ) with one beat notes except the last two, which are half beat each. The gender of each chord - maj. or min. - won't affect the run as the ear seems to understand where the lines are going anyway.
This change pattern is used often in jazz, and indeed can be found in most tunes, not always II-V-I, but still moving in fourths, so any of the above could be used in any tune to break up the monotonous I-V- I-V that bassists are expected to play sometimes.