I use 4 on current limits, but when I climp up I play only 2 and when I am comfortable I add another 2.
I play FL FR.
Add your tables carrefully, one by one. Some pros like Andy Bloch play only two, some others like Hevad Khan play 27. No rule here, only you can find whats suits you.
Here is multitabling article for silver, you can see first half like bronze.
http://www.pokerstrategy.com/strategy/fixed-limit/133/
When I work on my game like I read some article about flop play against one oponent, watch some videos focosed specially on that subject, I play only two and thinking more about this situations, grab some hands with Texas Grab'em and post for hand judge.
Try two if you want and if you feel pretty comfortable with your play on that limits, try add one more and you will see.
Be bless, qwery1
P.S.: If you need something write me, I help you if I know how.