First, start with a 'head' based kava like PK Hawaiian or Fiji or BKH Fu'u or Blackbag. These generally taste better than heavier, body kavas.
Mix equal parts of kava and Nestle Quik powder and then prepare in milk or milk like liquid (i.e. coconut or soy milk) - makes a pretty tasty brew. I would stick to 1 tbsp kava to 1 cup of water ratio because the stronger you make it the more kava taste you get (of course). Also use cold water/milk because warmer water brings out more bitterness.
Another trick for micronized powders (super fine grounds) is to put Nestle syrup (I promise I don't own any Nestle stock ;-) until it makes a thick, chocolatey paste. I then add a drop of orange extract (I found some oil based, instead of alcohol because I don't like ANY alcohol around kava, but that is just my paranoia). That makes a pretty good kava paste for your 'instant' kava needs.
Alternately go the opposite route, make super strong kava (always filter if you do this) and slam it. Of course, next time you are drinking whiskey, vodka or even black coffee, just stop and taste it - they really are just as bad as kava in their own way. It is just your brain associates good things with their consumption so you adjust yourself to the taste.