Mike,
I know leader attachment methods have been discussed before but I still like the braided sleeve for any line system where polyleaders are seldom if ever used.
Roman Moser braided loops are the only ones I'd use where a neat, short & slim finish is required. The RM silicon sleeve is the sleekest I've seen but that said I've reverted back to whipping the braid on as it makes an even nicer finish. I think that the merest (and I mean just a 'thought') of Zap-A-GAP or similar applied to the whip finish of the thread and then a slim coat of aquasure make for a finish that is nice.
Some of the vulgar braided sleeves are ok for connecting the backing to fly line but again I whip these onto the line. The thick silicone tube supplied with these is good for chewing while this process is performed.
I have in the past (and quite recently) attached backing to fly line using a nail style knot on 2 & 3 wt lines with the thinking being that the chances of this knot being outside of the tip ring very doubtful - wrong! A nice following wind coupled with a decent cast and an instant hook up and a lively fish had the backing well out of the tip on the 3 wt, with the subsequent swearing at myself for never learning from mistakes as the knot fouled most rings on the way in. twat! My point is that a slim braided loop is good here too, ok you still have to tie a grinner or blood knot for example but the transition through the rings is more than acceptable IMHO.
One last thing, I used to make my own loops but it's hard to beat the double skinned RM loops which have a very short and flexible 'ferrule bit' at the base of the loop - make them yourself 'traditionally' and you typically superglue the point where the loop re-enters the braid (or very near there) and this is where the stiffness occurs - I would suggest that the braid is double skinned to negate the need for superglue.
Just my thoughts
Two intermediate lines with double whip (just fancied a bit of patter) awaiting aquasure treatment
Iain
Iain