To powerslide, you must first build up speed. I would suggest stockpiling some Boost up by pressing forward on the right stick. Press
to use the boost, then let go of
and instead hold
and moving in any direction. You will be applying the brake and spinning towards that direction. Using a melee weapon and this technique, you can obtain double smacks for the damage dealt to the enemy. For this, I would suggest either Boxing Gloves, a swaying attack like the Bat or Chainsaw, or even trying the Vacuum and seeing if that works.