Just made a liar out of myself after stating I wouldn't try any new techniques for a while...
Working on Plastic Jesus, I was playing it fairly easily in G but that puts the melody a tad too high for my vocal range. C is about right but I was having some difficulty getting the playing smooth.
Then I had one of those "lightbulb moments". I don't know why, but I started playing the C chord at the 5th fret with two fingers fingering the 1st and 2nd strings rather than barring all 4 strings. Suddenly it just smoothed right out. Then I started playing a bit I've since discovered is called the "Galax" lick - raking down across 2 strings then plucking the thumb string, all in one smooth motion, to play a triplet.
These 2 things just (almost) instantly made the song a pleasure to play rather than a bit of a battle. Now I've just gotta get it smooth. Getting the Galax thing also translated into "Jesus On The Mainline", opening up the melody a bit more. And "Freight Train" looks like another contender for this lick, rather than having to make a momentary position shift or an uncomfortable stretch to hit the G on 5th fret of the 1st string.
And it looks like I'll be throwing a bit of drop thumb into "Plastic Jesus" to cover part of the melody I've been fudging a bit (timing-wise) up 'til now.
I'm trying to make stuff easy to play while singing, rather than have songs I really want to play being an obstacle course.
All in all, I'm quite happy now I'm back making recognisable (to me, anyway) progress.