I remember I first saw FLT using pivots at FC6, and then later, in more depth, I got to watch him play a lot at a tournament in December (Joe Michael 2) of last year. I thought, "Wow, that looks useful, I think I'd like to learn that." So in December I set out to do just that, and after working with it for a while, I realized, it's not
that hard to do, yet, it's unbelievably useful. In fact, it is the centerpiece to my game now, around January I totally restructured my game around it. It's really a trump card I have, an extra movement utility, that nobody else does. I still get ***** a lot though XD, even with such an amazing tool (I hate this game).
The method I use to do it (the real work behind pivots):
To do anything that requires left to right movement of the joystick (pretty much just f-smash and f-tilt), it's ok, and I advise it in fact, to use the "old" method of just timing the 'A' button in the stand-up frame of the dash dance (you know, the turnaround part).
Here is a secret I use for the timing on this one (everything tech skill related can be made easier by a "secret" to help you with the timing):
Let us assume you are Marth dashing right, and you want to pivot f-smash to the left. To do that, jam the joystick to the left fairly hard (not hard, but fast, don't try and break your controller). As the joystick goes to the left, keep in mind the time when it just passes the half way point (the neutral joystick position), but before it gets all the way in the direction you are going. That is when you press 'A'. The theory behind this is, the time it takes the joystick to travel from neutral position to all the way to the left is about one frame. If you can just press the 'A' button when the joystick gets in between those two positions, you are guaranteed a pivot. This works great for jumps as well (which means grabs too, always pivot JCed grabs, not only are they easier than 'Z' grabs, you are not totally lagged out if you mess up). Trust me, it works, here are some vids of my Marth to prove my points. Now, I don't claim to have amazing tech skil, and really I don't have all that much tech skill, that's not what this is about, but you can see that I have a pretty good pivoting game. Pivoting can be done 100% (although maybe not by me, but that will always be my goal, with any move), people just need to work with it more often and they will lose their fear of doing such a "risky" technique (I don't see it as risky at all, no more than wavedashing). I have a pretty good dash dancing game, and that makes it easier, usually you see people who are left handed (I'm not though) have better tech skill because they have better movement (the ability to control the left joystick more effortlessly; IE. They can move the left joystick faster and more presise, perfect for pivots.) I remember a thread by Ken a while back that described this inherited advantage, and I couldn't agree more. This can be overcome by practice of course, you just need to build the coordination/muscle up in the left thumb. Also, you'll see generally the best implementation of what pivoting is best used for (evading attacks, and striking back):
http://www.youtube.com/watch?v=iTJ0YaTdEo4
http://www.youtube.com/watch?v=Tid1sg_TWn0
http://www.youtube.com/watch?v=PL29VHfl1Bo
http://www.youtube.com/watch?v=V3VpUJg4h_M
To do anything else, you're going to have to use the "flick" (I call the FLT) method. I can't really help you on this one, you just need speed. Practice a lot and build up the muscle in your hand so that you are even capable of such an action. I also feel that keeping you thumb on the joystick at all times is impractical in this technique, as well as useless. Why is it useless? Think about it. Why is it that newer controllers are better for pivoting? The answer is, the joystick is tighter, therefore it springs back into position quicker.
Springs back into position. What I'm getting at is that you have to wait for the joystick to spring back to the neutral postition after the pivot anyway, and that's about how long it takes for your thumb to make it back to the joystick after the "flick", so how is it that you think the other method is faster? It will be faster just to let the spring flick the joystick back to neutral instead of somekind of inhuman manuver where you pivot and then immediatly go into the u-d-tilt.
There's also lots of added benefits of pivoting that you don't realize till much later, for instance, I've recently started dabbling in "Tree Grabbing", an extremely useful, although very very hard, pivoting technique. You can think of it as just creating an extremely large dash dance radius in which to pivot out of. But really, learn the basics of pivoting and exactly how it can help better your game before moving on to more abstract techniques that at first glance, you don't quite even know how it could be useful. In the context of Tree Grabbing, one of it's major uses is when you want to run away, like half a stage away, from the opponent and still be able to do your pivot grab, you now can!
One of these days I'm gunna get around to writing a tech skill guide, I'm just way too lazy to finish it... ...way too lazy...