When riding with a group communications between riders can be difficult.
The following is a list of common motorcycle hand signals for communicating between motorcyclists.
Use them as you see fit.
Note that they all require that you take a hand of foot off of the controls and this may not always be a good idea, so only do so when it is safe.
All hand signals use the left hand.
Remeber that not all motorcycle riders know all of these motorcycle hand signals, so many may not heed the warning or information you are attempting to pass along.
If you are riding with a group of motorcyclists it is a good idea to go through these hand signals so everyone in your riding group gets the message.