like several have said, HOW you wheelie is a personal preference, although theres some similarities and "standards" through all wheelies...
as mentioned...
theres a balance point, which is where your RPM's stop increasing.
theres what i call a "breakover point"... this is the point where its easier for your bike to overcome gravity... about 1/3 or half way up the "clock" to the balance point.
you can control both of these with your body position.
The further you lean foward, the higher the breakover point is, and the higher the balance point is.
The further you lean back, or sit back, the lower both of these points are.
Its a little different with a 12 bar, but not really.
Clutch it up, power it up, bounce it up, or use the rear brake to preload the suspension while you clutch or power it up... all does the same thing, it gets you in the air.
What you need to do, over and over and over, is practice one method of getting wheel in the air.... FORGET riding the wheelie out very far. Just practice the method you like to get the front up. OVER AND OVER AND OVER.
More importantly, do it at a constant speed.
So, you wheelie, say, at 10mph, and you set it down at 30... SLOW BACK DOWN TO 10mph, and try again. Use the rear brake to slow yourself down. This makes a mental link between speed and braking in your brain before you ever try to hit the brake in the middle of the wheelie.
Let me repeat that again. EVERY TIME YOU TRY A WHEELIE, SLOW BACK DOWN and try it again at the same speed. Don't keep speeding up. Then you learn nothing - you have no idea how hard to throttle / clutch it up at 10, and then you try at 30, and again at 50.... well, each speed is going to require a different amount of throttle or clutch, so keep doing it at the same speed. Once you master that, it will carry over to the other speeds more easily!
personally, i use EVERY method to launch a wheelie, but it depends on the bike, speed, and location.
For slow wheelies, that i want to consistently launch to the exact same height over and over and over, i use the clutch. On a light supermoto, you dont need much clutch or RPM's... just a little.
If i'm going around a corner and want to wheelie out of it, i romp on the gas.
on the highway in 4th gear, i'll stand on the rear brake to load the suspension, then clutch the SHEEET out of it and the combination of the three will get me up to balance point.
Heres an example of a 5mph wheelie at balance point.
and heres one a little past balance point... both of which i clutched up.
I actually pull my body closer the higher i get to scraping... its easier to steer, and gets weight of the back... i.e. it makes the balance point higher, or further back, so when i touch the 12 bar it hits softer....
anyway, after you master launching the front end in the air over and over to the exact same point, the "riding it out" part will come naturally.
If you dont master lifting the tire, then you'll continue to scare yourself by launching to high, or too low and then throttling it hard and nearly flipping yourself over.