@Tom_D, to your original question - These days it seems I do mostly finger-style playing. I use almost exclusively my thumb, index finger and ring finger and I rarely use the other two at all. I've never paid attention to not playing the same string twice consecutively with the same finger. As far as I can tell in some quick tests, it doesn't seem to happen very often. When it does, it usually makes sense rhythmically and it feels quite natural. It's getting a little late for me to do much about it, but I can see that being a useful general recommendation for someone learning. In my bass guitar lessons, alternating fingers and what to do with them when moving from one string to another is given a lot of weight. I am finding it worth my while to pay more rigorous attention to that than I did with my 6-string.