microdosing - first time

Looking to try microdosing for the first time. I was wondering what dosage I should take and with what frequency. I'm using 20mcg tabs. Never dropped before. I suffer from ADHD and am looking for an alternate source of medication than Focalin, Riddelin, Vyvanse, etc.. (Side effects f*cking sucked). Also a side note, I have OCD as well, and it's an anxiety disorder so not looking to get extreme paranoia or anything. Any advice is helpful! Cheers!