Tips to succeed in all missions

Stealth tips:

 * When guards notice you, get to the nearest hiding spot. Walk away calmly. Running away will only make them MORE suspicious. (Sometimes there are times when no matter how you walk you will get caught, figure out when these times are and kill or knock out the guard who caught you depending on if you can reach them before they raise the alarm, also hey, just a really big fan of entry point putting in what I think)
 * When guards detected you at a percentage of 90%, they will follow you for a while or you get away from their sight. So get ready to run, or deal with them. (Read above for my advice)
 * Guards will be suspicious of items on the floor and they will pick it up. Guns have the same effect but if a guard finds too many, they will radio. This can be used as a bait, or it's bad for you. (Hostage, KO, or kill the guard to get your items back.)
 * Cameras are dangerous, for they can detect you in seconds. Walk backward so they won't spot you. (Make sure to still watch out for NPCs while doing this, same thing still applies to when/if you disable/loop the cam)
 * When guards detect you from far away, shoot twice at them. This will guarantee that they will die. (I'm being serious when I say this, aim At the guard, not their direction)
 * Using the Silent Drill will help with certain things that just have to be drilled. You will keep stealth while drilling. (I have seen people dumb enough to think, because it can't be heard they can't get caught, Do not make this mistake, also on that note, make sure it is a silent drill you're using, before mission get rid of all the drills you have in your gear, then grab a silent one just to be safe, during mission check inventory for the icon transparency. If it is, then it is a silent drill. The loud drill icon is filled in.
 * Should you accidentally activate loud, you can always bring the III Frontline for the best possible protection. You can't go stealth with the III Aegis since you can't take it off. Hide everything in your equipment bag. (Always at the very least, bring in any armor, sounds basic or dumb, but any armor can be a lifesaver in a low stealth gone wrong at worst, at best your chances of survival are higher then they were before, at higher difficulties if it's not a trusted team, bring frontline, Always, go to take off your armor and press I to open your mobile inventory, always before you leave spawn double and triple check to make sure you have hidden everything you are trying to hide)
 * Don't leave your bags in the open. I know it sounds so basic, but I've actually seen people dumb enough to do it. No kidding. (I've seen this happen as well, they're not joking, also there are several places on every map to hide a bag if you're smart about it, I'm including the PvP and tutorial maps as well even though they don't use the bag mechanic)
 * Body bag everything you kill. (and knock out) No sense in letting a guard get suspicious of that weird bloody smell upstairs. Don't leave these out in the open either. Fun Fact! Citizen-type NPC's can't detect items in bags. Any bag too! (When able, find a place to hide the bag, dumpsters, cabinets, and chests for example, also read above)
 * Micro cams could help. You will be able to put one somewhere and come back later when you see your target. (This is true, on top of that if you have someone running 24/7 surveillance on cams then they can see more if you bring micro cams, also "latter" is spelled later if that was what you were going for)
 * Hostage VIPs or Guards for possible info. You might lose out on important things if you do KO or kill the person.
 * If you can, grab interference. It does not need a hacker to be nabbed. Same goes with Surveillance State. You can nab three set of extra eyes with is, being trackers, microcams, and camera hacking.
 * You just need to aim at people to hostage them.
 * Use the tracker on a VIP like Ross to know their location for the whole round.
 * The innocents can only detect bodies by their head. Use it to your advantage.
 * Don't bring any guns on the Killhouse. Take the supplied UP9s and bring lock picks and scramblers.
 * Now with the new camera update, cameras will detect hostages, dead or unconscious people, bags, and dangerous items. That includes guns, and almost all equipment.

Loud tips:

 * Don't just use the stock UP9 if you want to do loud missions because you want to save money. It ain't worth your life. (On loud missions you should always bring as much as you can while keeping a profit)
 * Bring the III Aegis, no matter what your class. People say it sucks when you don't have the Demolitions Expert perk, but it works fine on others. (Only do this on higher difficulties, frontline and below will work for op- if you're smart about it)
 * MED KITS ARE LIFE SAVERS!!!!!!!!!!!!!! (This is true, but don't go overboard, only bring in just Medkits if the rest of the team is bringing other gear, and just in case anyone says anything, yes I noticed they said nothing about bringing just medkits)
 * Grenades are effective at taking out enemies but can become quite dangerous. Their blast is so large that you can get caught in it. Don't risk higher level operations until you learned how to not accidentally kill yourself with a grenade like an idiot. (My advice, practice on rookie learn the range, check how you throw it, check how it interacts with the environment, just learn everything about it from experience before using it on higher difficulties, on second thought this applies to nearly everything)
 * Take care of snipers early on. They can get in the way. (Be careful about it, on higher difficulties not only do they deal more damage, but they also target and Fire faster, as a added "bonus" sarcasm intended they are mostly at farther ranges then you'd want them so a scope would be recommended in taking snipers down)
 * Flashbangs suck. Run away as far as possible when you hear that distinctive beeping. Shooting it is a horrible idea and only do that if you know there is enough time. (Or if you know where it is run away from that point, on that note cover and not looking at it reduces the effects, I think)
 * While it is commonly said that micro cams are only for stealth, you can actually use them in loud. They can let you take a quick peek at somewhere you can't reach. (I know they mean by "you can't reach" as in during the moment but I really want to poke fun at the way they put it. If you can't reach it how did it get there in the first place? No this was not just poking fun at them, try to make sure you have them covering as many areas and angles as possible, also if you have hacked cams try to make sure that micro and hacked cams views do not overlap) Maybe you'll be alerted when those SWATs come in a try to surprise attack you from behind... (This is true, also if you have someone just sniping then they can check the cam to make sure if anyone is sneaking up on them)
 * Make your stay a quick one. Waves get harder the longer you stay. (Do the objective whenever possible over killing whenever possible is a way to shorten your stay, either by dying or doing what you need to, also watch out for people who treat loud as a Team Deathmatch, they don't complete the objective and in my experience are some of the worst players to play with)
 * Proximity mines can help you defend a certain place better. This requires the Advanced Deterrent perk. (if you're planning on holding out for over a minute bring as many as your spare bag space will allow that you think you'll need, also still kill enemies to let your mines be conserved for when you need them; such as when they're overrunning you- )


 * Prep doing stealth-loud or setting up bags and C4. Might be helpful if you hack the PC in the financier before you go loud or hack the manager's PC before you go doing anything that swats will breach every minute.

Misc Tips:

 * Play with people you trust. Getting your items stolen or getting killed on Elite+ sucks.