Have you ever noticed how small and difficult to see most motorcycle turn signals are? To increase your visibility I recommend using the typical hand signals when turning. Not only does it signal your intentions, it also helps get you noticed by the cagers on their cell phones. Hand signals, along with a flicker of the brake lights go a long way toward keeping you safe on your commute by making you more visible.
There are many more signals intended for group riding, which I also recommend you get familiar with. Please see this PDF from the MSF if you wish to review them. Or take a look at this simple video:
Ride safe.