Classes
Spy - These guys aren't really that hard to face when in direct combat with one, so if they're far away whip out that rocket launcher if they're coming at you directly and weaken them before they can reach you. If they're still alive pull out your shotgun and knock them down a little further, and if they're still somehow alive, pull out the shovel and crack their head open.
Pyro - Now this is where it get's difficult. The pyro usually just w + M1's you to death, so you'll need to use the rocket launcher to narrow down the fight when they're coming at you from far away. then I recommend avoiding melee combat with them, just shotgun them until they die, if you use the rocket launcher to close it'll damage you as well.
Scout - These little suckers can be rather difficult to defeat with the rocket launcher if they're jumping around at random, so pull out that rocket launcher and attempt to twiddle them down to size, then when they're close use the shotgun, as the shovel isn't as helpful here, as they're usually too quick for it and will kill you before you do them.
Heavy - The heavy is much more difficult to defeat than any other, it'll usually take all four of your rockets to take down a fully healed one, so try and surprise them from above. If they have a medic healing them, kill their medic, hide from the heavy, then pop out and kill him quickly.
Soldier - Now seeing as that this is the same class as you, it makes it pretty even, as you have the same weapons, just rocket to where they seem to be running, then shotgun/shovel them to death or run away for health, then get back in the fight
Medic - The Medic can sometimes be a very high threat to you if you aren't paying attention, or he comes up behind you, but if he does manage to sneak up on you, don't waste your rockets on him, just pull out your shotgun for long range, or just whack him with your shovel.
Sniper - Usually if you're running at a sniper from long range, it will be very difficult to get to him in time before he pecks you off with his sniper. If you can get behind him, use your shovel to hit him a few times, then pick him off with your shotgun.
Engineer - Normally, if you see an Engineer, he has a pet sentry to protect him from harm, so if it's possible, just fire your rockets at the sentry until it's down, then run in and shotgun him to death.
NSFW: Click to View