Are you an antisocial, homicidal maniac tired of relying on others' skill (or lack thereof) to net you that sweet payout from Survival missions? Want to enjoy mowing down waves of enemies on your own, feeling like a badass the entire time? You've come to the right post.
Soloing survival missions is an easy way to net a large payout without having to worry about other players messing you up, though there are of course faster ways of gaining money and RP. When soloing a Survival mission, you'll encounter fewer helicopters than you would with other people in the game but otherwise they are the same. The strategies and spots I'll outline here are mostly for the benefit of newer players or people who just don't do survival that often. So without further ado, on we go.
Before I get into each individual map, I'll outline some general basics that apply to all missions. First of all, don't buy body armour at the start of the match if you don't have any - you can pick it up for free once the match starts. Some maps even start you off right next to an armour spawn, so that extra 100-500 bucks, while it sounds trivial, can be wasteful. Secondly, enable auto-aim. This will make taking out enemies that much easier, for a number of reasons. The most important one is what I'll refer to as 'mob management'. Mob management is when a large crowd (or 'mob') of enemies is approaching you and you're certain to take a large amount of damage unless you take care of them quickly. You could lob an explosive and try to take out a bunch of them, but I find it more entertaining (and cheaper) to quickly cycle between each target, shooting each once or twice to stagger them, preventing them from shooting. If done correctly, you'll avoid a potentially lethal amount of damage. You don't neccessarily need to immediately kill each enemy that appears - be smart. The AI's pathing is often not very good, and it often depends on the spot you're using to hide. They'll get hung up on debris or cover and you may have to venture out to kill them. Make sure you kill as many enemies as possible before you do this, especially in the later waves as those enemies are capable of taking you down very quickly, even alone. Speaking of waves, the first three waves are filled with very weak enemies. With the MG, it only takes a single shot to take them down, so to maximize profits, try not to light these enemies up with a full clip. Waves 4-10 have much tougher enemies that take a few rounds to kill (2-5 each with the MG), so save the Scarface routine for them. Finally, to deal with choppers, make sure you've killed all or as many of the other enemies as you can before leaving your spot to get a good angle on the chopper. You don't need to be shot in the back as you're trying to line up that perfect RPG/minigun/pistol shot to the pilot.
Boneyard is the easiest and most commonly soloed Survival mission. When the match begins, gather up any items you need and head to the green trailer south of the main building. Put yourself between the trailer and the wall and take cover against the trailer's corner (either one works) and get ready to mow down enemies. They come from both sides, so keep an eye on your mini-map and simply move along the trailer from side to side as enemies spawn. They tend to follow you based on which side you're on, but sometimes they'll try and flank you and might surprise you on the right hand side with a shotgun. The left hand side is a bit safer as there's a utility pole in the way that will partially shield you, so prioritze covering the right hand side. The RPG and minigun will spawn behind the wall past the gate to the east (right before helicopter waves, which are 4 and 10, sometimes 7 or 8 as well). It's close enough that you can sprint there and be back at the trailer as your preparation time runs out. Always prioritize having full health and body armour before a new wave starts in case of a mistake (they happen). When hiding behind the trailer, enemies will often just stand there pointing their weapons at you, allowing you to gun them down with impunity. The only real downside to Boneyard is that the enemies do tend to get caught up around the gate area, meaning you may have to either venture out and kill a few of them or be patient and let them come to you.
This spot can also be used quite successfully when playing with others, though note that the space is too narrow for players to pass each other, so you can get stuck outside if your partner is blocking the way.
Processed is slightly more difficult than Boneyard simply because the spot you'll be using encourages a much larger pool of enemies to attack you at once, much more aggresively than normal. When the match begins, grab the armour and any other items you need and head into the garage right in front of you. Run right to the back where you'll notice a large dumpster half full of gravel or some other gray, nameless crap. Hop inside and take cover against the side facing the entrance of the garage. It's very important that you are far enough from the open side of the dumpster that your character pops out from the top of the dumpster rather than around the corner - this is because coming from the top leaves you less exposed to enemy fire, and you'll be taking a LOT of enemy fire here. Also make sure that you're far enough down the 'hill' of gravel or whatever that your head isn't poking up above the top of the dumpster.
From this spot you'll be forcing all incoming enemies to come at you from one general direction, which is the entrance to the garage. The majority of them will approach from around the green cargo bin to the right of your position, and they'll be close enough that even popping out for a second could mean almost instant death during the later waves. This is where the mob management tactic I disussed earlier comes into great effect. Jumping around from target to target will prevent you from getting riddled quickly. If you see a large group of enemies approaching, make sure you've got a full clip ready as you don't want to get caught reloading in one of these situations. There's a red gas tank in here that can be blown up to kill enemies too, though most of the time they end up shooting it themselves and setting fire to their friends. Don't rely on it. Finally, be aware that the roof is somewhat patchwork, meaning that sometimes enemy choppers will be able to hit your through it if you're unlucky. Fortunately the minigun spawns literally right in front of you after wave 8 or 9, so it shouldn't be too much of an issue.
Processed is my personal favourite to do as the enemies rarely get caught up on debris or cover and they all come at you fairly quickly. You can get through this if done right in about 15-20 minutes.
I find this one to be a bit easier than Processed but I ranked it the same just because a mistake can cost you your life here. After gathering up your items head to the back of the tattoo parlour (big red building) where you'll see two recessed doors behind walls, kind of like bathrooms at a park or outdoor venue. One of them has a dumpster tucked away behind the wall too, and this is where you'll want to be. Take cover against the dumpster and get your most powerful shotgun ready (I like the assault shotgun, but if you haven't unlocked it yet any will do as long as you manage your clips properly). Enemies have only one direction to approach from and most will never get a clear shot at you, however sometimes they'll come around the dumpster right in your face, which means if you happen to be reloading or taking aim at someone else, you're probably about to get owned in a single shot. Pay close attention to your minimap and make sure you deal with these enemies before they get around the dumpster and shoot you in the face. Enemies also tend to get stuck on the other side of the wall as they know you're right there, but can't figure out why shooting the wall doesn't kill you. Either be patient or wait until the wave's nearly done and pop out and cap 'em.
I'm still working on the remaining missions - I've found some promising spots but either the enemies take forever to find me or it's too open to choppers and I get gunned down. Will update as I learn more.