Here's the deal, it's up to the more experienced (and I suppose outgoing) fans to rally those in attendance that don't know how to be most effective with crowd noise.
Here's a quick rundown of what I've learned about being a 12th man in attendance at a game. Oh, and this happens to be my 12th year as a season ticket holder.
I give people one simple "when to make noise" suggestion, to make it easy and that's:
Go bezerk any time the play clock is running pre-snap.
With your mouth:
Choose either to shout out whatever you'd like or if someone asks I will tell them to make a low, loud droning noise from deep down in their diaphragm (I would have spelled it like the birth control if I hadn't looked it up!).
OR
If you can do one of those "call the pigs in for supper" two-fingered whistles, DO THAT. I've never seen anything done LOUDER with a mouth (Pe may be able to weigh in on this though).
If you can use your voice at all, just a normal whistle will produce a little something, but you then really need to concentrate on making noise with your hands and/or firing up other 12th men and women to, as Pete would say, maximize your potential and have a peak performance.
With your hands:
If you are going to clap, take the gloves off and if you cup your hands correctly you can clap discernibly louder than a "normal" clap."
If you're not into, or can't clap for some reason, put a couple pennies in an empty beer bottle and shake away. My brother in law taps his ring on the railing in front of us.
Can you imagine if everyone near metal in the stadium was rapping it on it with another metal object at the same time??!
Really, a little coordination would go a long way. Don't want to be exactly like the Sounders, but their fans do come cool, coordinated stuff.
I really just want to hear the old, and much slower "SEA" "HAWKS" chant from the west and east sides of the stadium.
I will also tell you this, I've sat in the front row of section 316 for 12 years and witnessed many amazing things, especially during prime time games, but I'm going to do something for the first time this Monday...
Bring a sign.
Look for me (and my sweet sign), I'll be decked out in old/new school gear, with green "hair" pumping up the 12th man with everything I've got.
GO HAWKS!!!
P.S. Forgot to mention the obvious, nut make sure to tell people to shut up on offense, if you're going to do it right, you'll need the rest anyways. Those "Shhhhhh" things they put on the jumbotrons are just embarassing.