I would like to disagree slightly with the "do not speed above posted limits" tip.
If the posted limit is 65 and the flow of traffic is 70 (never mind the jerks in the fast lane doing 90), I'm doing at least 70 but probably slightly faster.
I was taught to ride just a little faster than the flow of traffic, even if they are exceeding the limit. Not much faster, just a mile or three per hour will do. This keeps your position among traffic changing and increases your visibility (we are all invisible when we ride). If you pace everyone else, you are going to remain invisible and get taken out.
If you ride the speed limit and everyone else around you is going faster, you are going to get rear ended or clipped by some impatient asshole. Californians absolutely love to see how close they can get to your tire or bumper before they make a lane change. They think the freeway is a NASCAR track and if they were allowed to nudge you out of their way, they would.
Now, you have to maintain some modicum of level headedness with this tactic. If traffic is going faster than you are comfortable, by all means ride at a speed that is comfortable for you but, don’t pace and don’t go too slow. Don't weave in and out of traffic just to maintain that one to three mile per hour faster pace; make smart lane changes. Establish your lane position, let those around you know you are there (safely get into their field of vision) and change lanes when it is safe to do so.
When we ride, we have to constantly minimize risk. Often when we minimize one risk we increase or create another.
In California, when you legally split lanes you minimize one risk (getting rear ended) and increase another (sudden lane changes, getting squeezed or if at an intersection getting taken out by a light runner). You have to judge for yourself which and how many risks you can handle and to what degree.
