Well, you lads keep complaining about Steel Hunter and I've been doing pretty decently at it, might as well share my method which has helped me grind through it in three or four days. Don't agree with the way I do things? Write your own damn guide in the comments.
With the daily missions you can only get so far. You need to get into that top 5 no matter what, and the higher you end up, the better. You might get away with a Harlequin, avoiding all fights untill the end, still finishing second – or you die. It sucks. Evading enemies all game does not give a reliable top three position, so don't do that.
Tank & upgrades
Harbinger or bust. My preferred upgrade path is Radio Cooldown -> Engine Dynamics -> Loading speed -> Armor -> Armor -> Big Alpha Gun. With the armor upgrades, this thing regularly bounces top tier incoming fire. You then need the engine to support that slow ass hull and turret. The big alpha gun is a beast when you use Berserker. Radio cooldown is always better than range because situational awareness is what keeps you alive and winning. Loading speed keeps you alive and killing midgame. DO NOT GET AN AUTOLOADER! They might sound nice in terms of burst damage, but they leave you vulnerable in most situations because it's not enough to kill a full HP enemy.
Abilities & ammo
Early game, shoot APCR at tracks and HEAT at front or rear – tracks will eat HEAT for breakfast. The exception is the Walkure, you can't reliably pen those from the front, so circle them with APCR. As the game advances, APCR + loading speed can shred enemies, so that's fine. Endgame: HEAT, HEAT, HEAT.
Corrosive Mist is not good for reliable damage, but it is a damn good smokescreen and psychologically denies an area. Use it for the latter then.
Berserker OP. Simple as.
Phase 1: Radio Cooldown & first kill
Your radio is your lifeline. Pickup two yellow drops ASAP so you get 500XP, go for cooldown. Do not use your radio yet. At this point, others have probably used their radio, you should be able to locate them. The only thing better than an isolated enemy is two of them shooting at each other. Let them finish, shoot the survivor.: it ain't pretty but it works. Be careful not to be the guy who overfocuses on his target, only to die to a number three. Most tanks will bounce 20-30% of their shots if you angle properly, so you should be the winner here. Once you're down to about 50% HP, pop your healthkit right after the enemy has shot, this way you get a 200-300HP boost that will make you win automatically. Kill them, take the pickup, and enjoy your boost to tier 3, maybe 4. Ping your radio to not get ambushed, and get a move on.
Phase 2: Scrounging for ammo, opportunistic murder
Your ammo is probably pretty low at this point, start moving around the map and fill it back up. The yellow areas are likely to have less enemies (the map is closing in where there are fewer players), go there so your are more likely to stay alive. They are also more likely to be alone, and you should be able to overpower them easily. Your goal should be to enter the endgame (last five remaining) with three repair kits, three medkits, two Corrosive Mist and two Berserker. Surviving to the end is more important than these targets, so use them if you have to (always use healthkits after a battle, they're worthless in a new battle). If you've got these consumables and you've completely upgraded your tank, stop moving, wait for the map to close up on these idiots.
Phase 3: Blatant murder
With the map rapidly closing in, people will be moving in a panic. You should not be, move as little as possible, try and keep your tank away from the yellow zones as much as possible. Allow people to run into each other and turn their twosome into a threesome. Using Berseker in any battle is an autowin at this point, nevermind if you track them and then pop Corrosive Mist right onto them. Ram that Harlequin, circle the Walkure, track that Varyag, and just shoot that Raven, there's nothing they can do. The only hard counter against this Harbinger is another Harbinger, and then it's just a matter of who gets their Berserker off first.