Just to toss another voice in here,
David is pretty bang on with his input. I use pretty much the exact same setup for all the web banner work I do.
I started out trying to fuss around with +Green Kinos to hit my screen, but have since learned that lighting from the top with soft lights is far superior IMO.
If I can't go from a ceiling grid I get my gaffer to rig up a pipe on roller stands so we can hang 2K softlights evenly spaced across the screen. The roller stands are great too because if the rigging needs to be moved we can lower the setup and just walk it back and forth.
I prefer a ceiling grid if I have the option though because it reduces your footprint on the floor giving you much more flexibility with your other lights. I find it helps the brain get more creative when you just need to think about lighting your subjects / can place your lights wherever you want. Blank canvas. Also, if you are worried about appearance, makes the set look nice, clean, organized, if clients are hanging around...
I think the biggest thing is to try and get as much space between the screen and your subject, I always push for the biggest studio space the budget will allow. Next to that try your best to have wardrobe and props steer clear of anything reflective. It's amazing how much simple production design changes can make your day run smoother.
Oh, I as well do a bounced fill 95% of the time.
Hope some of this helps!
Good luck!
Ian