For those horizontal surfaces, I use the timer function on my watch and go back every 15-20 minutes to smooth out the drips with a foam brush.

Here is a couple of thoughts:

 1) If you are laying fiberglass over your hull, leave a couple of inches or more overhang to catch those runs.

2) If you are doing a fill coat and have drips, I use a cabinet scraper to shave off the drip close to flush; then, I clean it up flush with a sander. I found one of the best tools in getting rid of drips in tight quarters is using a cheap Black & Decker mouse sander with its triangluar shape.  You can also use the mouse sander trangluar tip to sand drips down directly with little effect of gouging the surrounding area.

3) I kinda apply the fill coat epoxy similar to the techniques in applying varnish.   a) I use a chip brush to apply the epoxy to a 1-2 foot square area, pulling across the hull or beam to beam direction. Brushing on the horizontal surfaces and pulling the extra epoxy down the sides.  I then use a 2 inch epoxy roller to go from bow to stern (end to end) and smooth out the area I just brushed on epoxy.... You will then probably seen some tiny bubbles.  I eliminate most of them by using my chip brush, but this time tipping off the bubbles by smooth/light strokes from bow to stern (end to end).  The epoxy roller will lay down a more even coat but more thinly.  You may need to apply multiple coats.  My finally step is to use a heat gun to gently release any other bubbles.  Don't buy an expensive heat gun.  Get a cheap one from Harbor freight or Northern Tool.

Note: Do not use a big box paint roller!  Use a roller made for epoxy, like CLC sells.

Not exactly(but could be) a drip related solution, but I found that in cooler weather, foam rollers left a lumpy finish. So I went to the brush-on varnish technique. Foam brush using vertical strokes, followed by horizontal strokes a couple of feet at a time. This leaves a pretty decent finish without a lot of sanding required. Foam brushes aren't created equal. The ones I got at CLC held up much better that the ones I got from True Value, which, when saturated, were a little too flexible. YMMV. Dave