A nail knot using 20-30lb mono helps keep the bead in place above the hook as well. Some prefer to let the bead slide freely up and down the leader. I like it pegged in place with a toothpick. I think it is super key to use a very light mono/fluoro leader, 6lb to 8lb at the most, to let the bead move like a real egg in the subtle currents. Thicker test really stiffens the action of the bead/glo bug.

I like mottled beads in clear water with lots of light and clear/bright beads in dirtier water or lower light conditions. As Aaron said, experiment and don't be afraid to try some weird stuff. The chartreuse 10mil with a blood dot has taken a lot of fish!