#1 - A Virtual Tabletop is a MustMy favorite is Roll20, but I don't care what you use. No, you don't have to use one, BUT it saves a lot of time when you can show your players something rather than describe it to them. Best is a mixture of both. Further, Roll20 helps automate a number of functions like to-hit rolls and such with the use of macros and character sheets. I'm really just starting to scratch the surface after almost four years of using the service. Realistically, if you're playing for a one hour session (really about 40 minutes of play), the amount of in-VTT prep necessary to fill that session is pretty minimal. Further, if you prep a bunch in advance (say a level of a dungeon) that could be enough prep to last you for a bunch of sessions. One and done, that's my kind of prep.
#2 - Players Need to Be OrganizedMost of us are already using social media to organize games, sure, that's a given. Your players' characters should be on social media, too, and we should all have access to them so no one loses anything. Use that crappy part of the afternoon (you know the one) to write up session summaries. Talk smack away from the table. Share your Youtube links to Brad Neely shorts and snippets of MST3K ("Stump Chunkman!"). If the DM has access to advanced features of the VTT like character sheets, make sure they're entered properly. Junk like that. Sure, this stuff helps a normal game immensely, but will help a 40-minute-run-time game even more.
#3 - I Don't Care How You Roll Dice, Just Do It Fast!Some players prefer to roll their own dice and add things up, some players want to do everything through the VTT to "avoid cheating" (or whatever). Honestly, I don't care. Just do your rolling quickly, know whether you succeeded or failed or what AC you hit or whatever. Don't take up our time looking for your dice, trying to figure out how to properly parse a dice rolling command (Roll20 has a little pop out menu so you can just click the d12 to roll a d12, the d6 to roll a d6, etc, no need to fumble around with "r/ d12" when it's "/r d12," etc.) or looking up a ton of different modifiers and charts and other BS. Always be ready to roll, literally and figuratively.
+Donn Stroud can be a total baby and can't hang with the "hard mode" BX-style cleric!), I prepped once and d got I think 3 or 4 nights of gaming out of it (about 6-10 hours, somewhere in there).