Luckily for you, I main all 3 of those characters, so I can give you some individual pointers in each one!
Let's start with
Mario. Mario is one of those all around fighters; he's pretty balanced, and that balance is why he's such a good character.
*When I start my matches, I tend to rush to my opponent,
immediately grab and down throw, and then up tilt while they're trapped. A lot of times this'll catch the opponent off-guard and they won't be able to DI (direction input) out of the hits (if you keep doing this against friends, they'll learn eventually.) When they end up getting a decent percentage and are almsot able to escape,
end with an up smash or side smash, depending on where you think they're gonna land. This combo will land you around 30-40% depending on how well you execute it.
*Another good technique is
down throwing and immediately going into Up-B. This works from around 40%-80%, depending on the weight of the character (heavier characters will tend to get less knockback from your down throw, so you can do this a little longer, but use your best judgement.)
*
Charge up F.L.U.D.D. as soon as you can and as safely as you can. It's a really good asset to use against characters with poor recoveries or use their Up-B (which more often than not leaves them helpless) too high up above the ledge. Again, use your best judgement.
*
Aerials are you friend. Mario has fantastic aerials: his NAIR is instant, his BAIR has pretty decent knockback, and his FAIR is one of the better meteors out there. DAIR is also a great approach back to the ground.
*
CAPE IS OP. Use it to
turn away opponents from recovering, throw back projectiles, or to just throw off your opponent in general and punish.
Next up is
Jigglypuff! I'm glad to see another Jigglypuff main around here, she's a really underrated fighter!
*
STAY IN THE AIR. Jigglypuff is the Balloon Pokemon, so it only makes sense that she finds her niche in the air game. Like Mario,
her NAIR is instantaneous,
FAIR is great for walling opponents off the stage or for creating a Wall of Pain (ignore the back air part; like it says in the SSB4 section, it's more of a combo finisher in this game, FAIR is a better option), DAIR is a reasonable approach, and her BAIR has high knockback. Try to shorthop a lot and keep your opponent always reaching to attack you.
*
Rest only when you're absolutely positive you can land it. Rest is a really risky move, but when you land it, boy does it pay off. If you miss it though, chances are that you WILL be KO'd. (You're a light character; these things just happen.)
*
Do not use Sing. Sing has a small hitbox and leaves you utterly helpless. If you're oh so close to the edge but you might just barely miss it on your last jump, use it as a last resort to give you a tiny air boost, but otherwise, avoid it at all cost.
*
Lay down that shield pressure with Pound. Pound is really useful in a number of ways: for starters,
it's a good way to give you lateral air movement without falling and/or sacrificing another one of your jumps. Another thing is that
it has a really wonky hitbox and way too many active frames, which is good for you and not for your opponent. Sometimes if you think you're just barely gonna miss that Pound, you'll most likely make it. Finally,
it can wear down an opponent's shield to basically nothing.
*
Don't use Rollout to recover. It might seem like a good idea at the time, but a smart opponent will realize that
if your Rollout hits them and you're not above a solid surface, you'll go tumbling to your doom. Rollout, in the right circumstances,
can break a shield if it hits at full power three times against one and has pretty decent knockback, but just don't use it in the air.
Finally,
Ness! I was just training my Ness amiibo recently, so he's still pretty fresh in my mind.
*
Back Throw is one of Ness' most powerful moves. if you can get an opponent into your grasp with <100%, chances are that they're done for. Don't be afraid to pummel, either, he has one of the quicker ones.
*
Ness has a really good early percentage combo. It can either be done like Mario with an immediate rushdown, but it can be easier to
throw out a PK Fire and grab your opponent out of the flames, then go for an immediate down throw into a FAIR (sometimes two if you can manage it). This works a little longer into the percentages than Mario's down-throw-up-tilt combo, but take caution with being predictable and/or missing.
*
PK Flash is pretty conditional and should be used sparingly. If you land it, it deals a lot of damage and a lot of knockback; however, it's still pretty slow and leaves you wide open. It can be used as an edgeguard in some cases, but you'll be better off chasing the opponent down with a flurry of FAIRS.
*
PSI Magnet cancels your downwards momentum. Use it to trick your opponents into releasing an Up Smash early or just to play some general mindgames.
*
Ness has some pretty good aerials. FAIR can string opponents, DAIR is a decent meteor if you land it just right, BAIR has decent knockback, NAIR is a good approach, and the FOREHEAD OF JUSTICE (Up Air) is a killing move around higher percentages.
*
BEWARE OPPONENTS TRYING TO STOP YOUR RECOVERY. From Villagers pocketing your Thunder, Meteors, and just general getting in your Thunder's way, opponents can and WILL try to stop you. Ness has (arguably) one of the worst recoveries in the game (speaking from a strict "execution" standpoint, you travel a good amount if you land it.) Another interesting note I found out when training my amiibo:
if you hit an opponent while in PK Rocket, your travel distance will be reduced. Just something I thought would be worth mentioning.
Here are some other general tips that should cover all the characters.
*
Practice on a variety of stages. Mastering Final Destination isn't gonna get you anywhere. Go onto other neutral stages like Lylat Cruise, Town & City, Smashville, and Battlefield and learn the advantages and disadvantages of your characters there.
*
Rolling too much will make you predictable. Just don't roll a lot, trust me.
*
Sometimes, taking a risk is necessary. You think you can punish that recovery? Go for it! Learn the limits of what you can and cannot do.
*
Your mains WILL change in the future. This is coming from someone who can play almost every character in the game; you'll find better characters that fit your playstyle as it evolves and develops. Experiment a bit if you think you like how a character handles. Yoshi was my #1 for a while until I picked up Mario. I also used to use Lucina, Duck Hunt, Shulk, Captain Falcon, and many more in the past, but now I'm focused on Mario.
*Speaking of focusing,
try to focus on one character at a time. It's great that you can have multiple characters in your Bag O' Mains, as it can give you the upper hand when counterpickign in tournaments, but try to find a character you like the the most and
study the heck out of them. Watch professionals, play your friends, go into Training, do whatever it takes so you become be the best you you can be.
And that should hopefully cover it! Please let me know if you got any questions. I unfortunately cannot play on 3DS, but if you ever have access to a Wii U, I'd be more than happy to play with you! Thanks!
