What's your "finishing stroke" during cunnilingus?

TL;DR: I want to know how you finish your woman off once she starts getting close enough to go for it. Just the final stroke- I am NOT interested in the lead-up.

Hey guys and gals! Glad you made it to my thread. So here's the deal: The standard advice for oral sex seems to be that variety is fine when things are warming up, but that once you've started to go for the "O" you need to keep it consistent and unwavering. I'm wondering what some possible strokes are for when you are settling in for the "long haul" and you're trying to keep it regular. I know that every woman is different, but I have a lady friend who I plan on going down on this weekend and I want to have a couple of ideas so I can try them out on her and see which ones she responds to/are feasible for someone with average tongue stamina like myself. So here's what I'd like to hear from you:

1. How long is the MINIMUM lead-up from the moment your tongue is in contact with her vulva to the time when you start going for the gold? And try to be accurate. Aside: not enough people have a good concept of time during sex. I can't tell you how many times I've had people think that we just had sex for like an hour when it was like 15 minutes of actual fucking. And yes I time myself sometimes, it's for science.

2. Once you've started to "go for it," what position are your hands, fingers, lips, and tongue in, and how are they moving?

3. How long does this finishing phase typically last for you?

4. How's it working out for you?

Answers from everyone welcomed and much appreciated!