Gary, an aweful lot of the hunters you'll probably run into on So. CA beaches, are dry sand hunters. And dry sand has little rhyme or reason (besides the obvious "towel line", etc....) Not very many have mastered the beach erosion know-how. And yes, dry sand hunters will not have as high of a ratio of target counts, than those who have mastered reading when/where to do erosion hunting. I know a guy down there in So. CA, for instance, who has had days of up to 12 or 13 gold rings in a day, or 25 in a week, etc... during the major weather events. He'd look at your little gold ring and say "so what?". So yes, some hunters you might see on the beach are just sand-box caliber hunters.
There may be weeks (or even months) that go by for wet-sand erosion hunting, where you just stay at home without even going out (unless you want to hunt dry sand) because conditions don't merit it. That's the downside of waiting for erosion, is it's fickle, and infrequent. There are ways to watch the on-line buoys, weather, and marine reports to know when erosion is likely. And once you've ever been in mother nature's "sweet pocket", where you dig 300 targets in an area no bigger than your living room, trust me: you'll never go back to dry sand hunting again! And a bonus is that when those conditions occur, there is no light stuff at all. No tabs, foil, etc... All washed out to sea, in a natural riffle board effect, leaving only the heavier items on the wet. Ie.: coins, keys, sinkers, jewelry, etc... Those super conditions (where there's so many targets you can't dig fast enough) are rare, but they do happen after big storms. Stories of 10 to 15 gold rings in a day have occured, and coin counts so staggering, that the only reason a guy quits for the day, is not because he's finished his zone, but that the tide chases him back out, batteries go dead, or he drops from exhaustion! I've seen sickeningly thick days/spots like that, but only once every 5 yrs. or so.
I'm sure there's articles, books, and threads that you can find, about what marine conditions to watch for. And I will add that you have to take into account that they might be specific to certain geographic locales. For example, what weather/surf conditions that hunters in Galveston (gulf of mexico) looks for, will be different than conditions that a NY beach hunter (atlantic seaboard) looks for. And in CA, a central CA (where I'm at) hunter will look for different ingredients than you (southern CA) will look for, since you're facing south, and we're facing predominantly (with some exceptions) northwest. Each beach "acclimates" to its own set of norms.
But in short, you in So. CA would be watching for S to SW swells, above normal (whatever annual average "normal" is for your area), that occur during high tides, and preferably with on-shore or cross-shore winds. That's a very simplified explanation though, as it can get very indepth.
If you log on to the CA forum and ask around, I wrote and article that is in the archives there somewhere. That 2 part article is central CA specific, but with some adjustments, you can tailor it for So. CA. I'll have to PM you the address though, as it's not allowed to post links here.
And especially if you learn the in's and out's of the wet sand movement/erosion patterns, to learn when the wet sand will be good.