This helped me when starting out on this thing
iTaste VV V3.0 User Manual - Best Electronic Cigarette | E Cigarette Manufacturer| Innokin
Mainly tap both buttons at the same time and you get the number of ohms your current topper has (or NON if faulty or not connected), followed after about two seconds by how much
juice is left in the battery in volts (this confused me at first because I was seeing this number and thinking "wait I've got my voltage set to something else!").
Hold either the plus or minus button and you'll get a puff count, followed by your voltage(V) or wattage(P) setting (you can release the button after the display lights up). Once the volts/watts come up you can click plus or minus to bump up or down.
Change between VV and VW modes by holding the plus button and then holding the power button for VW, minus button and power button for VV.
I usually start at P=6.5 as mentioned above and then bump it up half a watt until the
juice starts to taste a little burnt - give it a few puffs before rendering judgement. Then bump it back down half a watt from that setting.
Oh, and click the power button three times to lock/unlock. Especially if you're going to pocket the thing. Forgot to do this last night and pulled it out of my pocket with a hot topper and the auto shutoff kicked in.