It depends on the kava for me. As you know I am relatively new to kava but I have definitely noticed that I can get pleasant (rather than manic) effects from relatively small amounts of certain kavas. 2 kava candies are enough for me. A tablespoon of Quick Kava or Instant Green do enough. Kava kauia's Vanuatu waka medium doesn't take much. I had 3 tablespoons of Pentecost Pride yesterday and I think that could be my favourite so far, really pleasant.
I forgot to say, I'm definitely onto something with my milk thing. Have your kava, eat something small then drink half a pint of milk...