With my players I try to find a way to say yes to some of their crazy ideas. I figure as long as it doesn't break any fundamental rules, like one player was wanting to try making a device that would spoof the matrix into thinking it was actually him instead of a device, I say let them try it. Few things can take the sails out of player engagement than a GM who seems to always say no when the players try to do something. If there aren't rules for it, just pick either a stat and a skill you think would be close for it, or a couple stats and see what happens.

If you can't find the rule in 5 seconds, make one up and tell people you'll get back to it afterwards. Dead air time kills a session fast. To help making a GM screen of some of the rules that you find hardest to remember is always good.< This I think is a great rule of thumb. Keep the flow of the game going, and it goes with what I mentioned a bit above. Also I'd recommend, if you write down your session plan, put some notes where the relevant abilities you are less familiar or comfortable with are. In the last run I did, I put in the notes the table of matrix actions, which showed the action, simple/complex/free, and skill/attributes to use it, along with a short description of the action.

Also make liberal use of email to communicate between sessions to get both their individual feedback, and to discussing consequences of actions in the future. The second part is more for new players, since they may need some guidance into fully grasping all of the consequences of their actions. Like my current group will get some reputation and street cred after their current run. The first time I hand waved over it, but did mention it to them in email and at the start of our next session that going that flashy would probably get them some of the above (they crashed their Roadmaster into a building to try ramming a mage in the hallway). This session they rammed their Roadmaster through the garage door to breach a warehouse building, and then have been making liberal use of grenades inside the building.

If you have options 1, 2, 3, and 4 for how you think players will go through your adventure, know they will often pick option 5, so be mentally prepared to go of script. This will also help make them think you are really well prepared and have all of the angles planned.