With FK425 very little goes a very long way, particularly after your microfiber towel gets a little damp. A light mist is more than enough to cover an entire panel (half a hood/door/trunk,half roof/etc).
My suggestion would be to only squeeze the trigger about half way and move your hand quickly so you lay a thin, fine mist over the majority of the panel. Then spread it around/work it in, flip to a clean side of your microfiber, and buff.
Alterantively you can mist directly onto the microfiber and wipe in.
Todd this post had me thinking why would you recommend using such a small amount if you had any dust it would not be enough to lubricate and you would risk marring the finish.
The only thing I could think of is you are using it on a already clean car.
This morning I used FK425 on one of my cars that only had been driven 20 miles on pavement since it was detailed so while I'm sure it had some dust it was not visible.
This morning I used FK425 on it and it worked pretty good but I had a bottle of Lucas detailer that I had tried and did not really care for it either so I had been letting it sit on the self.
The Lucas and the FK425 both was easy to use and I could see NO difference between the two after applying.
The Lucas cost half what the 425 does so if you factor cost into it that would be a better choice.
If you use 425 on a clean car it works pretty good but no better than several others.
This reminds me of something I posted a few years ago on the old DC forum I took my car to a show and on one door I used a very expensive LSP on the rest of the car I used a LSP that cost 1/10th what the high end one did.
Not only did I win an award but I told dozens of people what I had done and ask them if they could tell it and they could not.
What does it prove, While people look for a magic bullet it don't exist.
The prep is the important part when you get the car prepped right then nearly any LSP will look good.