One misconception is that Spies cannot be Scouts, Hwguys, and Soldiers. This is not true, and turning always run off is not always an bad option, but not usually prudent. For soldiers and hwguys (The move roughly the same speed) use the tap technique to move forward. (i.e. Tap the +forward key on your board at a constant rate to make you move slower, if you dont do it right you look jerky, but most players attribute that to lag!!)

Another thing is to befriend the other team. Hang out with snipers in the nest, and pretend to aim. When they're not expecting it, Knife 'em. Doing this constantly drives them insane.

Drop grenades and/or gasses around the guns to take them or the Engineers out, then quickly change skin. It will keep the defense guessing.

If an enemy resupply room is open, chuck a gas in there and you'll seem like Hitler..

Dress up as a medic and watch for Helpme! calls. Fun galore.

Good spies take out sentries. Coordinate this with your team's assault. No sense wasting your grenades when the defense will just build more. Grens DONT BLOW YOUR COVER!!

DONT GET CONFUSED! A spy has so many color and skin changes that you might accidentally gas or attack your own team. Watch out!

On maps like Canalzone, a spy is near useless for anything but spying. Infiltrate their base, gas it up, or take out snipers and report on enemy movements. That's it. Dont try to capture a CP unless you are playing against a totally incompetant team.

On the Rock, those spotlights are your enemy too. Wait till someone runs in, and the run in with them, you stand a better chance against the snipers. For more fun, run in with a member of the enemy team.

Sneaking around the Rock is hard at ground level. Try jumping up the lockers in the bathroom. You have acess now to one enemy resupply point, and noone expects you there.

On any of the 2 fort maps (2fort4, 2fort_32) the underwater entrance is your best bet. Dress as an engineer and hang with the guns in the basement.

If you are caught, kill whoever caught you, and run like hell if possible. Then switch colors and skin.

If a map has invisible spies on, leave. It is not worth it and a lot less fun. And if you have a chance, complain about it. Invisible spies suck... A Lot..

You will never be at the top of the frag list unless you are lucky or very good. Frags aren't what counts, so dont go out of your way. Captures are important. And you can do that easier..

Beeline escapes are easy, but are usually fatal. However, make enough long winded escapes and the enemy catches on. Alternate your routes to keep them all guessing.

People get annoyed when you knife them in the back for the 300th time. Be a good sport and smile when you kill them. Laughing sadistically is not that bad either, especially when he waxes you too.