CBN is the secret sauce for sleep. THC begins converting to CBN at around 150c so infusing flower at this temperature is a good way to make sleepy oil.
ive been self experimenting with this for a while, I can say that including CBN did help to improve the quality of my sleep, however ive actually had better relief when ive dabbed CBD isolate with THC , those were some of the best sleeps id guess around 90-100mg CBD and a small dab in between size of grain of rice and 2 grains of rice of resin (thc % approx 70%)
It also seems best that you start consuming a few hours before and lead up to it rather than 1 big hit right before bed (But an additional big hit before bed also seems useful )
CBN, CBG, CBN-O, THC-P/HHC-P (be careful they're wicked potent), and delta 9 are all the sleepiest cannabinoids for me subjectively, but some people around me claim that delta 9 and CBN-O are not that sedative for them.