If you have a 3DS, you should play Fire Emblem: Awakening. If you don't have a 3DS, you should get one to play this game. It's that good.
But once you have the game, how can you make the most of it? I've had to impart some Fire Emblem tips to some friends and colleagues lately. I figure you should know about them, too.
Play with permadeath on
Classic Fire Emblem games saved after every tactical move you made, making the death of any your misplaced minions "permanent." While you could always restart a mission to keep your virtual chess pieces alive, it was usually so much of a hassle to do so—to have to replay so much of a mission all over again—many players would just learn to accept these deaths. Each death stung. Each made you play a bit better. Awakening lets you play in a casual mode that removes permadeath. Avoid! Play in "classic" mode with Permadeath on. (If you're going to restart missions a lot, the easiest way to do it is to wait for your turn, select "bookmark" from the options menu, let yourself get kicked to the title screen, then go back in and select "continue" to restart the chapter you were on—assuming you saved between chapters!)
Arrange your teams before the start of battle
The game makes it clear how to pick which units to send into a mission battle, but it's less clear how to make sure they're standing in the right place. Before a battle starts, select "view map" and then start swapping your units' positions until you have everyone standing where you want them to.
Arm your people with health items
Every soldier should go to battle with a Vulnerary or Concoction, so you can raise their health if they take too much damage. Your healers can't get to everyone.
The left shoulder button is your friend
You're going to be marching a bunch of units around a lot of maps. You're going to want to do this swiftly and cleanly, giving each unit the proper orders before shifting to the next one. You might think that the best way to do this is to use the D-pad or the Circle pad to move the game's cursor. Wrong. Tap the left shoulder button to cycle from one unit to the next. Or move the cursor manually to an enemy, then use that left shoulder button to cycle through all the enemy units. Take note of which weapons they have and if any of the enemies have actual names. If they do, it means they're either the boss or a character you can recruit. If it's the latter, don't kill them! Talk to them, using one of the game's heroes, Chrom.
Always press the X button at the start of a battle
This displays the movement and attack reach of the enemy, designating which squares are safe, and which are not. There is zero reason to have this turned off.
Choose the correct weapon
Awakening gives players an extraordinary number of ways to customize the flow and display of the game's battles. It even offers a couple of different ways to pick your weapons. Here's the thing: make sure that, when you are about to have a unit attack, that he or she has the correct weapon equipped. The correct one isn't always the most powerful one. If, say, your unit is near archers or mages, who can attack from range, you might want to attack with a weapon that can be used up close and at range. Why? Because, when it's your turn to have your units defend, they will use the weapons you equipped them with to attack. Also, notice that each weapon your heroes wield has a number next to it. When that number drops to zero, the weapon breaks—forever. So don't let the game make you use weapons that you'd like to save for more dire situations.
Watch your flank
Many of the game's better, tougher missions involve enemy reinforcements showing up late in the battle. Prepare for this! Don't leave your weakest fighters behind.
Level up your weak fighters
It might be tempting to only fight with your strongest characters. Don't do that. Bring some of your wimps into battle and safely, carefully let them get some potshots in so they can gain XP and level up. The weakest characters often can grow into the strongest.
Wait before upgrading classes
There is no sweeter feeling in a Fire Emblem than leveling up a lowly beginner unit to their new, uber class. You can do this as soon as they hit level 10. Resist temptation! Each unit can hit level 20 before their stats max for that class. Get your units to 20, then upgrade their class, for max stats growth. You'll notice that your units will also gain powers as they level. Two per class. Some ensure a unit will survive if it is attacked when near death. Others allow units to rally (read: boost stats) of nearby units. Learn these powers and use them.
Always, always, always pair your units up. In Awakening, adjacent units can lend support during attacks and defense. Some units can support each other more potently as they improve their support ratings (not all pairs can do this; check the support menu to make sure your ideal combo of units is compatible). But it's more efficient to have your units pair up on the same square instead of just standing adjacent to each other. These pairs become super-powered duos. They can gain an incredible level of support affinity, almost always complementing the others' attacks and counters. The best pairs are the S-rank pairs, which can only be attained by units who marry. Since each unit can only marry one other unit, you need to do some careful matchmaking.
For better or worse, Awakening allows you to grind. You can send your army out into the world map to skirmish against characters sucked in through Streetpass, Spotpass or, it seems, a faked version of Streetpass. Do this. Fight these other units. It will beef up your weaker troops. And since the gameplay is fun, this isn't so bad!
Protect your winged characters
NEVER fly a flying character within range of an enemy who has a bow and arrow. NEVER!!!
Always go to towns
Send units to the front gates of towns. The townspeople always have something to give you.
You'll never be able to use all the 40-odd characters you can round up in this game, but recruit as many as you can. The characters are all a lot of fun. They're chatty and some of them are excellent fighters.
Don't upgrade weapons
There's a forging system in the game. I'm not sure why. Default weapons are powerful enough. Maybe this is important at the game's hardest difficulty? I'm at the middle level of difficulty and have never needed to buff a weapon. Plus, all the weapons break. That said, there's not much worth spending gold on in this game, so if all that loot is burning a hole in your pocket, go wild.
Check the barracks on birthdays
The barracks are the goofiest part of Awakening. You can go there to watch your fighters chitchat, randomly gain XP and other weird things. But also... when it's one of your fighters' birthday they will get LOTS of extra stuff in the barracks. Or at least that was the case for two of the three Kotaku staffers who tried this on Gregor the swordsman's birthday. You should try it, too. Check the in-game roster to see when the birthdays are.
Play with the 3D on
Some of the later battle missions look amazing when the 3DS' 3D is on. The effect adds a lot of texture to the terrain. Even better, the game's anime cutscenes are stunning in 3D.