Mass Effect 3

- For your first time through, play Soldier, Sentinel, or Infiltrator. Biotic powers are actually quite worthwhile now, but so is shooting things.

- Don't feel bound to the types of weapons you were using in the first two games. Wanna play an Infiltrator with a shotgun and an SMG? Go for it. How about a Sentinel with an assault rifle and a shotgun-pistol? Sure! Use the shooting range on the Citadel to get the hang of your new gear.

- Some guns can only be found on missions and are missable, so look around!

- Complete armor sets (the ones that cost 50000) have kinda crappy stats. Don't bother, unless you like the look.

- Do every sidequest you get before doing the next "Priority:" mission. The exception is Eden Prime, which is the mission for the DLC character.

- When given the choice between betraying your old friend, and getting the support of the other race, stick with your buddy. You can get the other guys' support anyways later on. If I had to tell you that for you to make that decision, you're an asshole.

- It IS possible to make the warring races near the middle of the game get along, but if you didn't do the loyalty missions for the two squadmates involved in ME2, or got one of them exiled, you won't be able to do it. If you don't manage it, know that at least one of them will die.

- They make it fairly clear when you're about to go on the point of no return mission, but for the sake of it, it's a mission called Priority: Cerberus Headquarters.

- If you're going for a perfect ending, you need at least 4000 "Effective Military Strength", which is your Total Military Strength combined with your Galactic Readiness (Defaults to 50%). You can get 4000 EMS without playing multiplayer, but it requires not missing a single war asset. I didn't quite get to 4000, so I had to play multiplayer a few times to get my Galactic Readiness over 60%. You should know that a large amount of the War Assets aren't tied to any side-mission, so I'd recommend using a guide which lists all of the scannable locations in the various systems, and going around collecting them all, if you want the perfect ending. It'll help a lot.