Super Smash Bros./Samus

Bomb Recovery : This is not so effective when recovering from a low position off the platforms, but when knocked far to the side Samus can easily recover from distances most other characters wouldn't dream of. Using Samus' Bomb attack(Down+B) and pushing the direction you want to go, Samus will roll into a ball and drop a bomb - but she will remain lateral, not falling further while rolling. After the bomb attack she will return to normal form and begin falling again, which is when you can initiate another bomb attack. In this method, Samus can slowly but surely move back towards the platforms, using her final (Up+B) recovery to get back on the platform if she needs. A strength of this particular tactic is that, if high enough, it gives some flexibility in returning to the side platforms. Samus could recover up(Up+B), drop further bombs and land on the platforms, drop fast to grab the edge, or come back with another attack.

Spike : (Down+A) While jumping, do an A attack down, Samus should do a quick spin kick towards the ground. Timing is crucial when doing a Spike(Which can be done with other Characters, but not all of them), but when you have knocked an enemy off the side, jumping out to meet them while they are still not over the platform, then executing a Down+A attack, will send them quickly towards the ground with very little chance of recovery. This attack can easily KO low precentages, as long as they are knocked off.

Charge Shot : Pressing and holding B will charge up a shot, but you can also interrupt this charge and do other things. What does this mean? Every spare chance you have, you should be charging. Enemies must always be wary that you have a fully charged shot, that can do upward of 25% damage and send them flying. This will not only obviously make them more cautious towards you, letting you take the initiative but also gives you a ranged attack to send at them when they least expect it. Do not make the obvious mistake of simply lobbing projectiles from the far side of the map hoping to hit someone randomly. First off, an uncharged shot is good for little more than annoyance in most cases. So you should only attack with a charged shot. Secondly, you must look at your enemies current tactical positions - are they recovering, which direction are they moving, etc. Shoot when you are almost guaranteed to land a hit, when they are in the air recovering, attacking someone else, or otherwise preoccupied mentally or physically. If they see it coming, but their character is simply in no position to move out of the way, fire. There is no reason that the attack MUST be ranged, a charged shot could be a perfect end to a melee combo, or it can be fired at relatively short distances at a charging enemy. Further uses of the charge shot include using excellent timing to hit an enemy that is recovering from the edge. If an enemy is already off the edge, recovering, a charged shot USUALLY is enough to send them out for good. Charged or uncharged shots are also good for getting the last damage in on an enemy, ensuring that the kill is yours(Whether you actually earned it or not.)

There are some other notes to take with Samus.

Grapple - Samus's throw is pretty dismal, and the range is more of an impedement than an asset. Do not attempt to get into throw fests with other characters unless you are sure you know what you are doing. When Samus misses her grab, she is vunerable to ANYTHING for quite some time as her grapple comes back in. This aside, the grapple does have a range advantage, and can be used to pull one enemy from another melee for free damage, or hit a charging enemy off gaurd. At maximum range, the grapple also can just barely grab a Hammer wielding enemy for a throw, but this is tricky to pull off.

Ground Juggle - Like all characters who can spike, Samus can also juggle towards the ground, using ground attacks to keep an enemy pinned while she racks up damage.

Smash-A - Samus's smash punch is pretty powerful, but also reasonably quickly executed and should definitely make up the brunt of your melee combos.

Back-A - Samus's back jump kick, pressing and attacking in the direction opposite of which she's facing, is also reasonably powerful and can easily send enemies off the edge in an ariel bout.