There is a lot more to "Clouds Bro" and you gotta practice. I suggest low or 0 nic, otherwise... its nic sic for sure. 100% VG with no nic or flavor gives the biggest clouds.
You should also notice in the vids, when they do the ramp up exhale, they also lean forward. This is to force more air out of their lungs so they can inhale move vapor one the inhale part. My full pull is usually 3.0 to 3.5 seconds (ramp up and inhale).
Next part takes some concentration.. holding your mouth position to exhale vapor in a straight line.
And of course getting used to massive vapor clouds so you don't choke and cough and look like a fool in front of your friends (or room full of cloud chuckers if you compete. lol)
right now i'm at 12 nic. every once in a while one of my tonsils will hurt like i have strep throat or something. so i'll switch it up with 9 nic. and i use the typical 70% VG. i haven't gone down to the lower subohms, i'm happy now at 0.4. and my pull is 5.0 to 5.5 seconds, very slow and deep. i started vaping a little over two months ago and i'm slowly gearing up to building coils and blowing big clouds. hence, watching all those youtube videos or reading forums. i don't know anyone who vapes so i have to get all my information online. but even if i don't graduate to advanced vaper, i still love all the information. that's half the fun of vaping, there's so much to learn and it's all fascinating. my friends think i'm nuts.
oh, and by the way, i tried the quick exhale and, yeah, my clouds were definitely bigger. nice!