A grid to play on. Either a large chart, or some graph paper. You can
use miniatures, scrap paper, toys, or whatever to represent your
characters on the map. Another good idea is to laminate it and use a
dry erase marker to draw terrain and characters on.
A lot more d6s. However many you have, you probably could do with more
when someone breaks out the Extra Attacks on Burst Fire.
Cut out some common blast template areas (such as spheres, lines, and
cones of scales 1 and 2) from the Template section of the appendix