This has been done a million times before. Just post a pokemon who you would like to give a new move/ability to and post said move/ability. If you give it a new ability, you can't give it a new move and vice versa. You're also not allowed to give more than 2 new moves. And try to make the buff as sensible as possible.
My buffs: Ampharos: Tail Glow (seriously...)
Bannette: Swords Dance, Mach Punch
Ariados: Speed boost (Aren't spiders supposed to be really fast?)