Snorting works wonders in kicking my pills in fast. I prefer to either plug my first pill or eat half and snort half. If I just eat my first pill it seems to take forever to kick in. It's also a much more intense rush up to the peak.
The downside of all this speed of intake is that the amount you insufflate won't last as long as it would when eaten. It's perfect to start off a night, but I wouldn't use your whole pill or stash this way.
Tilting your head back is done to keep the drainage flowing down your throat instead of out your nose, where it would be wiped away and wasted.
Also, in my experience it has been easier to get a pill chopped up into powder than it has been with cocaine (I live in the south-east, so the humidity makes coke a bit sticky sometimes). Just go at it the same way you would coke and if you take the time to do it right, it will be a powder in no time.
Just watch it, as the pills seem to explode when you crush them. Make sure you're careful and have the pill covered or your pill will end up all over the place when it breaks apart.
In the end, though, if you really want to get more out of your pill than just eating it, plug it. Snorting does work, but the shortness of the roll (at least for me) is really only worth it if I intend to do multiple pills in the evening and really want to get started fast. Even then I'd probably go with plugging, it's just less of a waste. (I don't think that you actually lose MDMA, per se, but that it's so quick on the uptake that you get an short roll, which is less fun if you intend to party all night.)