25% on the high cap coins (BTC, ETH etc). 50% on medium cap coins (ARK, LISK, EOS, Waves etc) and 25% on low cap coins (NAV coin, Deep Onion, Pearl). You mimiize loss that way and you would expect some of your low cap to explode.

Something that most say but few follow is if that 20K is a lot of savings for you do not invest it. You will end up sweating over Blockfolio and Delta. If on the other hand your life would not be shattered if you lost it I wish you good luck