BigWigs » Participant
When the fight begins
BigWigs automatically senses the nearby presence of a boss and enables the appropriate bossmod without delay. Normally, you're not required to do anything.
The BossBlock plugin is the main thing keeping your sanity during boss encounters. It blocks any raid warning text that is determined to be boss announcement chatter.
Most people will want to have all the BossBlock options checked, they will only block what you will be notified for in the BigWigs message frame anyway.
If you get hungry during the raid
BigWigs comes prepacked with a module for starting custom bars, which is excellent for when your pizza is in the oven. Just throw that baby in there, run back to your computer, and execute /bwlcb 720 Pizza!. 720 seconds is 12 minutes, which you'll obviously want to configure to your liking :)
This bar is local to your client, and others won't be able to see it.
Moving the bars and messages
The bars and messages plugins for Big Wigs can be moved with an anchor that can be toggled on from the plugins submenus Bars and Messages. After moving them, the test plugin can give you a couple of bars and messages to test your position and if you're fine with it.
Remember that there are several bar textures available, as well as several output locations for the messages; for example SCT or MSBT.