Team Fortress 2/cp dustbowl

Dustbowl is a popular attack/defend CP map with multiple stages.

Scout
Like many stages in Dust Bowl, the Scout is relatively useless to start off with. Going Medic, Heavy, or Soldier would almost always benefit your team much more. However, if all of RED's sentries are down, switching to Scout can get you into the first point quickly and if your team is with you, you can cap before RED has a chance to recover. Also, going out to the second point before the first has been taken and then waiting for you team to take the first cap can sometimes work, but RED's engineers won't always be caught off guard and will sometimes even build at Point B at the start of the game or not long after. This is often better preformed by a Spy, as the Spy will have more uses behind enemy lines if Point B can't yet be taken.

Engineer
Defending Point A is conditional, and depends on the number of Engineers on the team. With a single Engineer, it's a good idea to build your sentry where it has range and line of sight of the capture point. The most common place would be inside the capture point house on the second floor. This area is out of view from BLU team spawn and an ubered enemy will usually not be able to reach it before the uber wears off. With multiple engineers, building on top of the shed near BLU spawn is a decent option, but this will likely be BLU's first target. Building a sentry in the lower levels of the cap house is tempting but inadvisable. Rocket spam or a smart demo can take this one out a lot easier than a sentry placed on the shed roof, or especially second floor cap house. Other spots for rebuilding downed sentries or numerous engineers would include the open space a few paces back from the shed, or near the health and ammo reserves next to the one-story house in the back.

When defending the B Point, the primary place for a sentry is the left corner of the cap area, right where the health and ammo are. Getting a dispenser here is vital to the team, so try and do that as soon as possible. Metal here shouldn't be a problem because you're right next to team spawn, plus there is a small ammo box located right next to where you'll be building. Enlist the help of Pyros for spy checking when you can, and never drift from your position. An uber coming out of the top can still kill you and destroy everything with relative ease, so be wary. Having more than one Engineer to defend Point B will help this. A second sentry is best placed next to the fence on the team spawn side. It isn't as well protected and can't cover the cap but has a much greater range and vision of the field than the sentry in the corner. With two sentries going and careful attention to spy checks you should be able to hold this point until time runs out. It's one of the easiest points to hold in Dust Bowl, and RED has a huge advantage if done correctly.