I apply it upside down, to fairly wet hair, all in one section. I do one small squirt then scrunch it up into my hair. I don't put any on the very top or sides as I don't need much hold there. A little definitely goes a long way. Start small!
I'm a joiwhip newbie but I've been applying 1 squirt (grows to about kiwi fruit size), all at once, start at roots and work to ends, head hanging upside down. I do a leave-in first on very wet hair, then CurlKeeper, then squeeze out excess liquid with hands then JoiWhip. Then I pat a little gel on top. That's way more products than I've been using, but it's been working.
(my dogs aren't snarly, my hair is)
My hair's a bit past shoulder length and I use maybe a tennis ball size amount. Divide it between both hands and work it into my (wet, in the shower) hair from roots to ends. I kind of rake and squeeze it in, no scrunching.