So...whats yer secret?
The Mike Meanza/Josh O'Connor team placed 1st in year 1 and 2. Clan Yeoman placed 1st or 2nd in 3 out of the 4 years that this tournament has been running. Those teams must be doing something right.
I wouldn't just single us out. Just off the top of my head, here are a few more that you should ask for advice - Glen Eagles, We Flunked Flank (already mentioned in this thread, but worth repeating...plus, these guys are really cool), Fish in a Barrel, Simple Weapons, The Blood Kings (won the tournament this year)...I think you get the idea...there are lots of great groups out there . Any team with experience in the tournament could give you some good advice. I appreciate the nod though.
I'll reiterate what Joseph has already said - playing the DCC tournament modules is your best way to prepare for the tournament. Read the scoring, and know where points are typically assigned.
Other Tips (I'll probably regret this later)
Pregens - know thyself.
Take time to study the characters. I'm a BIG dork when it comes to the tournament. I lay out an excel spreadsheet, with each character, side by side. You want to make sure that you have the bases covered in terms of the skillsets. Knowledge skills are largely overlooked by most people...don't be one of them. I've been playing D&D since I was 8 years old...but I'm not an encyclopedia. Sometimes I need a reminder on what creature weakness are. For that matter, the Goodman folks are pretty clever and often add templates to standard creatures...
Look carefully at their magic items. There will always be something useful. Use them sparingly (since they cost points)...but don't be afraid to use them. You can use A LOT of charges before it equals the point deduction that you suffer for a PC death. Keep that in mind.
Since Goodman Games (currently) provides 6 characters and you only play 4, that means that even the selection of PCs is strategic. Different teams will have different tactics. Ours is fairly consistent each year. It doesn't always work to our benefit...and some rounds we BARELY made it past encounters because of our choices. In any case, we generally go for this mix - thief, cleric, mage, warrior. That means we leave behind A LOT of the muscle...but it suits us fine. Thieves are essential in the DCC tournament. Don't leave home without one. The mage provides the surprise spells and area effect stuff that will get you out of tough situations. Clerics provide the healing (necessary, since you'll be taking more damage if you leave behind the muscle PCs) and turning. Lastly, the warrior provides your front to combat.
I would suggest matching the PC mix to what your team is most comfortable with.
Play the Pregens before the tournament.
It lets the players become more familiar with them. I generally make up a tournament-style adventure to get them accustomed to the PCs.
Go quickly, but carefully. This is a difficult balance sometimes. Don't get bogged down in time-consuming combats. Having everyone rush in is not always the best tactic.
Pick Your Players Carefully
You've heard the phrase "too many cooks in the kitchen". Well, the same applies to tournament groups. TOo many leaders/type A personalities will hurt the group...even if they are the best players in the world.
Avoid Over-use of Magic Items in your regular campaign
I'm not sure if everyone feels this way. In our regular campaign, we're poor in magic items. The downside is that we often have to look up what the magic items do (prior to the tournament). The upside is that we're more likely to approach encounters a little differently...and I've always felt that was an advantage.
N'Haaz-aua mentioned We Flunked Flanks tanking tactic. Also, here are some general tactics - luring opponents into different rooms (used a lot this year), bottlenecking opponents (let's you fight less of them at once and you can provide your strongest warrior as the "front" man), using distance weapons to your advantage, using spells to weaken opponents before the warriors rush in, etc. Use the tactics that work best for each room. Use the terrain to your advantage. Don't neglect the benefit that cover can give you.
Adapt or Die
Yeah...like the dinosaurs.
The Goodman team has managed to make enough changes each year that the teams have to respond a little differently each time. So...be adaptable.
4E will change everything
It probably doesn't need to be said, but 4E will definitely throw everyone for a loop, and it will take some time to adjust to the new system. Such being the case, new tactics are bound to show up. Read the rules carefully and look for creative loopholes (I know I will).
Ummm...that's all I can think of right now. Hope that helps! See you next year at GenCon.