(copypasted post from my past)
if youre struggling learning 1t flicking, i recommend installing this "histogram" plugin (far too annoying imo to leave on, but it can be useful to get a grasp)
in this image the cyan lines are the tick boundaries and the darker blue are actions
when i 1t flick i try to compensate for the fact that i have at least 45ms of lag from my network + whatever brain latency making my finger click and lead the first press just before the tick start