I work at a cell phone store and I've put on hundreds of these things so here's my method:
1.) As most people have mentioned, dust is bad. It's the #1 reason for bubbles. So clean that baby with surgical precision, not one spec of dust should be left on there, not even a tiny one. (I've never used the shower trick but I can definitely see how it would help for this)
2.) Once all the dust is off and I mean ALL of it (can't stress that enough) line up the protector with the
film still on it just to see how it lines up.
3.) Start at the bottom. Make sure you line up the home button but equally important make sure the sides line up. If you don't have it lined up perfectly straight this is where you'll get screwed, because you'll have to pull it back up and re-align it. If that DOES happen, don't panic. Just peel all the way up to one of the bottom corners and rotate the screen protector where you need it. This is where a dust-free environment is important. ANYWAYS once you're lined up as best you can tell, peel a little bit back at a time, squeegeeing as you go. Seeing as how big the screen is, it would be a good idea to take your time and try to get most of the bubbles (especially the ones toward the center) out now to avoid complications afterward.
4.) Now that you have the whole screen protector on there, it's likely there will be a few bubbles. This is normal. If you paid attention and made sure there was NO DUST anywhere, you should be able to get every single one of them out with the squeegee. Get most of these with the outer protective film still on. Then peel it off and attack the rest of the bubbles, laying this film over those areas to protect your actual screen protector. You should be able to get all of the bubbles out and have a crystal clear display.
Remember the number one rule:
ABSOLUTELY NO DUST! Not even the tiniest little spec of it.
I figured this is what you were wanting in the OP instead of people telling you whether or not to get one

Good luck!!