[Zador]

Physically, Tape over your webcam (if you have a built in one) and remove any external ones.

Download Tails to a USB and connect to a VPN before connecting to Tor.
Use NoScript to disable ALL javascript and flash.
Don't download anything, You never know what kind of 0 days a seemingly innocent file might have.
If something looks sketchy, It most likely is sketchy.
Never share your private information (First/Last Name, City, Country, State, Age, Anything that is identifiable.)
If chatting online use a username unique to Tor. Don't use any of the usernames you would use on forums like this one and never use the same username twice.
When you're done browsing close Tor down completely before disconnecting from your VPN and shut your PC/Laptop down, Then remove the USB.

Happy & Safe Browsing!