As SkinGriz notes, route selection should be at the top of your list.

A flashing helmet light often (but not always) can be used to get driver's attention. Make sure your other lights are bright, charged, or have fresh batteries.

How you ride is important. You're riding with the traffic, correct? Right in the U.S., left in the U.K., etc. Ride a straight course, at least a foot or two away from the curb or fog line. Do not swerve in and out around parked cars; nobody can see you before you pop out on the back side of a minivan. You're better off riding steadily in the right tire track (for U.S. riders) than swerving in and out.