I like nitrous (wippets) while rolling.
Blows you up like can you say what, what?
A couple of boxes of nitrous through the evening really keeps the roll going longer and blows you up again during the comedown.
THIS.
If I want to make my roll the absolute best (which is actually every time I do it these days since it's not that often) I do the following:
MUSIC - It was said already, but this is key. Good electronic music. I know some people like to listen to rock on it, but it's sac-religious to me. I like what was said earlier about it tickling your mind, it really does take you somewhere else. I have a big collection of albums to choose from. I'd recommend at least one album of good psy trance, you'll love it.
MILKDROP - If you don't have winamp on your home computer, you need to get it! This is the best visualizer I have come across. It's awesome. The TV in my living room is attached to a home entertainment computer, so it's very easy for me, but if you have an LCD TV, hook it up to your computer to watch the visuals while you listen to music.
WHIPPETS - I know these concern some people, and I would never advise anyone doing something they don't want to, but I highly recommend giving it a try, even just a little to see how it feels. It'll blow you up and seriously take you to a whole new level of rolling.
PAJAMAS - it's silly, but rolling is pretty silly and I love this. Very comfy!
I also always have a vicks inhaler, weed, and menthol cigarettes. I hate cigarettes sober or with anything else, but rolling they are seriously amazing, consider giving it a try if you have not.
So my perfect rolling night begins with listening to music and watching milkdrop and doing whippets every so often. If you have the luxury of a significant other to share it with, do it! It's sooooo amazing to just sit and listen to music and blow up and smoke weed and cigerettes and make out and fuck while rolling. We like to eat it at like 3 am in the summer, so we are rolling when the sun comes out and then we spend the rest of the morning in the yard, though we have a nice private property. It's a really great experience and IMO all of these things really maximize the roll.
Have fun!