I'm going to have to start off with stating the obvious. Falco is the clone of Fox, and because of this he has virtually the same moves, with a few minor exceptions that make him much better than fox!
Falco is a falcon, Fox is a fox. Fox is heavy, Falco can practically float. When playing with fox or Falco, the main thing you need to know is that you are playing two of the fastest characters in the game. When you play Fox, you have to act fast, jump into action and be prepared to have to change your decisions based on the enemies movements at all times. That's why Falco is better. You have to use his ability to move more slowly as a method of being more precise. He's fast, and built solid (So he's not unstable) The perfect combination.
Enough. You don't care about that. What you do care about is "How do I become ferocious with Falco?". Here's the start. Get to know all of Falco's moves. The obvious moves that people repeatedly do are the straight forward power attacks. Tap+A after Tap+A after Tap+A and that's not the way to win. One of Falco's most unique and effective move is his down A. Don't tap it. The best way to do this is to hold the control stick about downward at about a 45 degree angle. So you don't Down A attack but you do kneel. Then hit A. Falco will flick his tail out in front of him. This move is amazingly powerful. At about 100% it can knock opponents off. The sweetest part about this move is you can do it in a split second. There's no way for your opponent to see this move coming and when your in the middle of close up combat this move is tons of fun to throw in. Say "See you later" to your opponent.
Falco's second most cool move would surely be his downward kick (The screwdriver kick). You can do this move anytime in mid air by pressing the control stick down and pressing A. If you tap the control stick down Falco will come down at a really fast speed. Falco's Down A attack while in mid air is one of the coolest attacks in the game. One of Fox's major flaws is that his Down a attack while in mid air totally sucks ass. His recovery time on that move is longer than your opponents when your opponent gets hit by it. Not the case with Falco. Use this move anytime. While your on the ground wrestling with someone, take a leap up and give 'em a straight kick down. It'll send your opponent up, allowing you to continue with another move for large combos. Also, try to use this move to intercept idiots trying to get back onto the ledge who think they can get through you. If you get good, you can leap off the edge towards the enemy, pound them into the ground using the screwdriver kick and get back on. It'll really piss them off, by the way. This move sends an opponent hurling towards the ground and then they usually bounce off the ground and head up. Don't you think it would be especially cool for there not to be a ground to save your enemy?
The last important move you have to get used to is Falco's B-down. The reflector shield. Now, I, like most other Super Smash Bros. players saw this move on Fox on the original Super Smash Bros. And though "Oh my god! What a dumb move, they already give you a shield! Why the hell would you need to?". Well, let's just say Falco has one of the best shields in the game. You can get some of the most deadly attacks off it if done correctly. Learn to use that shield whenever someone may throw something at you or shoot something at you. There's nothing more satisfying than to watch your friends character fly off the screen like a missile because he was stupid enough to throw a bomb at you! The Ferocious Falco! After you get good with it, and it hardly ever fails, your friends and enemies will begin to catch on, and will probably hesitate to throw things at you, making them fear you! Shooting things at you is a little harder to to, but you can see a bomb-chuck coming a mile away. (One of the coolest things about the reflector are you can reflect regular shooting attacks, and you can hit people when you are touching them. It's fun watching Link draw back an arrow, release it, have it hit your reflector and have the perfect trajectory to head back and hit him).
Falco lacks very many good combos. But there are three I always use.
1) kicking. You can run and kick people by tapping the control stick in the direction you want to head and pressing A. You can hit a person, and they will go upward. If they don't have very much percentage they won't go very far. As a matter of fact, they'll hit the ground right behind you. Why don't you turn around, and give him another kick up into the air, and repeat the process? That ought to really piss 'em off eh?
2) A cool looking but really weak combo. When you grab an opponent press down on the control stick to send him to the ground. After Falco shoots the character immediately press B-Down and turn on the reflector shield. If your opponent is close they will get hit. Giving you two moves in one. That bastard level 9 Fox loves doing this to you....
3) Other than that, there's just the regular kick combo. Not the repeatedly tap A combo. The Smash Attack after Smash Attack after Smash Attack. (The move being referred to is the head-high kick Falco does). If the person has a low enough percent and isn't light like Pikachu, you can repeat this move two or three times. Especially on a big stage like Corneria or Hyrule Temple.
1) Obviously when your close to an opponent you won't wanna be pulling out your laser unless you want a kick to the face. If you've kicked an opponents ass away from you and your enemies are fighting on the other side of the stage, that would be the time to pull out your laser and add some percent to them while they're far enough away for you to respond before they can attack you. When they run, you shoot, when they come for you, they shoot, and right when they think they're gonna hit you, you kill.
2) The Superscope. What a Falco friendly weapon! If you see an enemy charging that gun, jump in the way and pull out your reflector. It is impossible to stop charging the Superscope without releasing the shot. The shot will rebound off of you and head in a perfect path back to them. Not a thing they can do about it. Chances are that an idiot holding a Superscope will act just like a dear caught in the headlights. They won't know what to do, so they'll hold it in to stay safe for a little longer. They never let it go early. They'll hold it until it's fully charged hoping that something will happen to stop you from reflecting it. You'll hit 'em almost every time.
3) A move easily overlooked. Not much to say about it though. When in mid air put the control stick in center, and then press A. Falco will just do a regular karate-type kick in mid air. Looks harmless and useless but it's not. This move can hit people the whole time Falco comes down. Not just when he kicks, but for about 1.5 seconds after it too. A long move that you can execute while your friend thinks he's gonna hit you and you'll already be doing your move and they'll be the one getting hit.
Well, It's my opinion that Falco is the best character in the game, and with practice, you too can learn to absolutely murder your friends with Falco. Be sure to check some of the other character guides coming out soon, and they'll be more strategy on this soon too!