Roll and tip

So in all of my painting research I must have come across the phrase "roll and tip" about a thousand times. I really blew it off and didn't think twice about it. Until I was rolling my third coat of epoxy over the hull and I kept getting all these bubbles in the finish. I thought that it was supposed to get more smooth as I rolled more coats on! So I grabbed a little 1" wide brush and started drawing the tip across the surface of the epoxy. Viola! No more air bubbles. Why didn't I try this earlier? And why did I use this little 1" brush? Anyway, it worked awesome and I am relieved that I figured this method out before my paint looked funny. The epoxy is thick enough now, but I think I will put one more coat on after sanding this one smooth. I also read that for maximum time savings you can roll on the second coat of epoxy after the first is tacky, but not set yet. Coats 3 and 4 are dry and hard now so I get to clean and sand one more time for the final coat. I am now taking input for paint colors...