Avoiding cheap deaths in TF2
In addition to learning the maps, there are a few other things to know:
- Sentry guns beep 1-3 times each time they change directions (so about every 3 seconds). Once for mini/level 1, twice for level 2, thrice for level 3. Generally, if you can hear a sentry's beep, you'll be in its range when you round a corner.
- As a Spy, you'll get a LOT of cheap deaths. Sadly, this is because of the Spy's shortcomings in order to combat the instant-kill backstab.
- The Spy's Dead Ringer takes some getting used to, but in certain situations, using it (preferably while disguised as a teammate so they don't know you're a Spy) can get past a defensive line. Beware that the Dead Ringer makes a louder than usual decloak sound. The Dead Ringer is a "perfect" cloak for the first 6.5 seconds, so enemies who touch you won't make you appear as a team-color outline. However, they still can't move through you.
- The Cloak and Dagger gives you some latitude by not decloaking when you don't want to, but it also has a very short cloak time.
Having said all this, you're still going to die a lot in Team Fortress 2. It's the nature of the game! The lower-HP classes in particular are specialized in some way, but lower HP is the drawback.
As a spy, you will die. It is unavoidable. However, there is a difference between staying alive and being effective. For a spy, your jobs are to:
Report on Enemy movements from behind their lines. (Yes, like a real world spy). Letting your teammates know what's waiting for them without the enemy knowing that their secrecy has been compromised can give your team quite the advantage.
Take out the high profile opponents. The Heavy-Medic combo, the fully-charged Sword Idiot, The Sniper. Beyond these 2 roles, as you try to run around and make regular kills, accept that you will die, a lot. In regular play, the Spy relies on enemies making a mistake more so than he does his own "uber leet skills". Just be in the right place, and know how to take advantage of any lapses in your opponents judgement/security. If your enemies DON'T make a mistake, and most decent players won't make many, then you'll realistically only win about 1/3 face to face encounters, less if you're discovered while cloaked.
Once you've played on a map fairly often, you'll come to know the favorite paths and firing lines that people use as they duck in and out of cover. Obviously as spy, you will want to avoid these as much as possible, as that's where you're most likely to get hit (either by bullets or bodies) assuming you're fully cloaked. Even in the tightest places, like a hallway, one side a half-step away could easily be much more hazardous than the other.
Scouts should follow similar rules, especially on maps where people will fire blind (mild spam), but they are much tricker and very dependent on enemy positions if you're trying to make an end run past the front lines. Bonk Cola always makes it easier, but if a Pyro, Soldier, or even Demo is hell-bent on running you down, it can be extremely difficult to evade them. If you use your teammates as distractions, you might be able to give that Pyro something else to fixate on instead of you.