So many variables go into making "big clouds". Some you can control, some you can't.
Mostly with the TFV8 there's little you can control, just airflow and wattage. So the advice can only be to open up the airflow and pump up the watts to the point you're comfortable at.
With an RDA pretty much everything can affect your 'cloudage'.
I've found simple builds work best, 5-wraps of 24awg on a 3mm bit is a good starting point.
Wicking material and how it's wicked. I use Cotton Bacon that is slightly snug through the coils and cut it so the ends just touch the deck, the DO NOT tuck under the coils, this helps the next part - airflow. You want the air hitting those coils full on and you want good airflow across the entire build so line up the airflow with the coils and don't restrict it by using too much cotton.
Next is your juice, go for as high VG content as you can find and keep the nic as low as possible.
Things like your anatomy are out of your control. Lung capacity and how hard you can inhale will have an effect but there's little you can do to change that.