For our regular Tuesday night races, we only recently came into having regular committee to run starts and keep times again. Before that we agreed on course on shore, one boat would volunteer to run the starting sequence on the water, and we'd all keep our own times. We certainly did not want to have a team on shore when they should be sailing! We use nav marks and semi-permanent marks set out by the local keel boat fleet, and pick a course around those based on prevailing conditions. When we've wanted to set our own mark one of the sailors would drag it out behind his boat and set it on the way to the start. Honesty and sportsmanship are required for tis approach...
Now at least, we've reached enough critical mass to have folks who enjoy coming out and helping with the starts and time-keeping. But that is done from shore on the Pirates Cove pier - we always have the same starting line. We have no committee or crash boats, sailors know that they are on their own. Because of all this, our races come off as kind of cross between windward-leeward and distance races. Our starting line is never square to the wind, sometimes we start downwind, somtimes upwind, etc. etc. etc. But it seems to work.
The few invitationals we've done aren't that much different, except we defintely try to have committee!