Tricks and Tips!

Be your own sentries cover wall

don't be afraid to try

Plan ahead

Small aggression

Watch the score board

Watch your own team

Help out your co-workers!

Shift working

Active platforming

and because the physics in this game are very accurate to real life

Found on the wiki

Keep your children fed

While your sentry is building you can't repair it (unless you've picked it up then placed it again), so if you accidentally (or intentionally) build a very aggressive sentry that is taking minor incoming enemy fire, you can walk on the other side of it, and take a few shots for it.If you had full ammo when placing it, you will use 130 of your metal, which means you got 70 left after placing it - that's not a lot, but still something. Trading 20-40 of your health for 20-40 of your metal that you would have to spend if you let your sentry get shot while building. In my opinion, it's worth it most of the time. When it's up, you will have 70 metal to keep that little thing going and doing a lot of damage.Even if it goes down after having scared them of or stood there for a at least 3-5 seconds shooting, they lost way more value. Either they lose the area which gives you time to level up your sentry, or gives you time to move it up one more time if you have team mates with you, or they lost health and have to retreat.Another thing you should keep in mind about your sentry is that it will spawn with 1 hp. If anything hits it, it will be destroyed, so in the first 2 seconds of your sentries building time is when it's the most important to body-block any damage. If it goes down, 130 metal (-the scrap parts you are able to pick up) will be wasted. Butaggressive sentries, they can often change the outcome of the game.If you plan ahead that you will make an aggressive sentry you can build up your sentry right before an aggressive corner, pick it up and then move it so it has a line of sight to your enemies, this does so it won't spawn with 1 hp. And it also builds faster, way faster!When you move a level 3 sentry, the initial building process where it goes from a toolbox to a level 1 can be sped up by hitting it with a wrench, me and a bunch of friends tried being 5 engineers hitting one sentry, and it went up instantly. The issue is though, the animation where it goes from a level 1 to a level 2 cannot be sped up (same with level 2 to a level 3), so before you move up your sentry, keep in mind that when you move up a level 3 sentry, it won't start shooting before a demoman has already had a chance to place 4 stickies on its feet.This one is HUGE for engineer, especially if you're attacking. Look at who's playing what, and get to know your enemy team a bit - who can mess you up the most. People with higher scores are usually bigger threats to you. When you see maybe top 3 on the enemy team die, or number 1, 2, 4, and 6. - you move your sentry up. And move it up far, because when a sentry is up and being taken care of, it gets very hard to take it down.To keep yourself away from looking at the scoreboard all the time just memorize the names of the top two players on the other team, when you see them die or if there's a lot of enemies dying in the kill feed, check the scoreboard.It's nearly the same as the last one, if a heavy medic is close to the front line and just ubered or if you see that they are rushing in to pop the uber, put your Nike or Puma on and get those legs going, you're pretty much guaranteed that the enemy team will be running away, and enemies running into their spawn or back line is the same as them being dead.A sentry with two engineers hitting on it is close to invulnerable, nearly nothing can take it down. When the action gets hot and going, maybe a heavy is jumping the sentry, or an uber combo is pushing in to take down his nest, it's both yours and his interest to keep the sentry up. It gives you space to push aggressive sentries up. Maybe while he has nothing else to do he will level up the sentry just just passively placed in his domain while you're on the frontline doing damage with your shotgun.Continuing on the previous tip - if you notice he is not around his sentry, or you noticed he got killed, take his place for 20 seconds and keep his sentry alive, killing the engineer is often a big part of taking down a sentry, people often write messages like "engineer down" in enemy team chat, to signal that they can easily go for the sentry. However, if you're sitting there, you may be giving your fellow engineer a few kills and gaining yourself a couple assists as well.Since you can stand on your dispenser, you can use it as a platform to get to some places you previously weren't able to get to.you can also pick up your sentry while jumping off of it. This can make you very unpredictable, and pulling it of in combat can be very rewarding.I found this great picture on the wiki. I wanted to mention the advantages with high ground and I think they nailed it pretty much. so here's a little screenshot of the wiki and a link to it , all credit goes to them. I would like to add though, that you can pull the sentry back a little bit to make it harder to hit while still maintaining the firepower. I edited the wiki picture to show as an example.Health and ammo packs spawn every 10 seconds, so when you start building up a nest, pick up the ammo pack as early as possible to get the next respawn as fast as possible. Try to time it so when it respawns you're already standing on it.