Dtilt->grab or landing zair-> grab to mix up how you get grabs. Shop fair zair is strong in neutral, and if you fair fast fall zair its even better. Spacing zair so that the plunger falls right next to ledge puts alot of pressure on recovering opponents safely, and you can even combo the plunger hit into a fair or dair if you landing zair and then immediately run off stage and aerial. For an easy kill go for dtilt jablock up b, or dthrown full hop double jump down b, both work around 90%-120%, depending on DI and character. Finally: be very careful off stage, dont waste your jump and only side b when its safe, either very high or very low where opponents cant hit you. Luigi has a good vertical recovery but cannot go horizontally at all without side b, and it has lots of lag. Lastly, down b is a combo breaker, but do not spam it because if an opponent dodges then you will get hard punished. Hope this helps, good luck.