Ev training advice / suggestions for a Competitive team?

Hey everyone.

I'm making a competitive team and i'm not sure what to use for my Ev's.

so far I have a mudkip with perfect Iv's and Curse/ waterfall and avalanche.
I'm not sure what to put his Ev's as. Should i give him 252 Hp/252 attack/4 defence? Or 252hp/252defence/4 attack?

Also, i'm hopefully getting a ferrowthorn with 31/31/31/31/31/31 iv's.
How should I Ev him also?

I may also get a Flawless Larvitar.

How should I ev him? I'm assuming I should put 252 ev's in Attack of course. But should I but the rest in defence? Or hp?


Thank you for taking the time to read this ^_^

I look forward to your responses!