Do you have something like iReal Pro or Band in a Box to play with. If not consider a purchase, it's worth every penny.
Something that has helped me is to get a standard tune, whatever you like. Go through the form and play the root on the downbeat (something your examples do a lot). 2nd time through the form put the 3rd on the downbeat. (yup you guessed it) 3rd play the 5th on the downbeat. This shows you many things, but the 2 biggest are, 1.) learning to spell the chord members quickly, and 2.) you don't always have to have the root on the downbeat.
When you've gotten the ear and mind freed up on the chord members, you'll find you have a lot more options at your fingertips as you improv a walking line. Note that 4-1, 5-1, and half steps are very powerful interval movements to clearly show a downbeat (you don't always need the root). For instance moving from Cmaj7 to Cm7 putting the E natural on the fourth beat and moving to the Eb first beat of next measure is a strong move and really shows the modal change.
Another thing to consider is the shape of the phrase. Using the root on the downbeat for the opening of the phrase and the closing is strong, but then using other chord tones for the middle measures can give some direction to the energy and make the phrase stronger. This applies well to the standards and can also work well with other styles.
Lastly, if you can play the melody (again, good practice with iReal Pro) then avoiding melody pitches on strong metric beats makes your line stronger and the music more complete. Flat 5's are very lovely sounding pitches and they are very fun to play in a walking line, but if that's the melody note, the effect is lessened. (Autumn Leaves is a good example of b5's in the melody).
One more thought... try to do a different line every time you play a song. Don't find an answer and stick with it, you'll not learn as much.
