I've seen a couple of videos an blog posts discussing James Taylor's slight tweaks to standard tuning so I was interested to see what he had to say.
In the video below posted from his YouTube channel he recommends tuning each of the strings slightly out of tune to compensate for the use of a capo and the fact that the bass strings ring out of tune when they are struck.
To do this you will need a metronome that shows how many 'cents' you are from 440 tuning. A cent is 1/100th of a semitone (or half step). In summary, Taylor recommends you tune the strings a certain number of cents below standard tuning (i.e. when the tuner is telling you the string is perfectly in tune):
Low E = -12 cents
A = -10 cents
D = -8 cents
G = -4 cents
B = -6 cents
High E = -3 cents
Have a try and see if you can notice the difference.