I've tried many different methods but the most efficient one is mixing your kratom powder with water in a 500mL bottle (I usually use about 200mL of water), the key is to shake it well so there're no lumps. Then you can just drink it all in like 2 seconds, you barely taste it that way (though I'm not really bothered by its taste). Some people use juice to mask the flavor but I don't think it's necessary if you do it right.
OT:
Besides the drugs I listed on my previous post I'm also a big fan of LSD, tripping on acid is one of my favorite things in life. But I don't consider it my DOC since I barely do it nowadays (same thing applies to DMT).