Any tips for relics? Or places to go sluicing?
I'm not into gold-in-natural form (nugget shooting, sluicing, etc...) So I can't comment on that. But in-so-far as "relics", I'm assuming you mean also where coins can be present . And not just "farm junk" ? Thus perhaps you have places like stage stops, ghost towns, cellar holes, etc... where you'll angle for lantern parts, harmonica reeds, pistol balls, gun parts, and all sort of cool age-indicators, right ? And then hopefully a seated or reale or gold coin on a good day hunting such sites, right ?
If so, then I refer you back to my original answer: If anyone had any such site , still giving up 4-star gimmees, they're not likely to tell. They're going to harvest it themselves. You simply have to "one-up" your competition, hit the history books, and hopefully find new sites on your own.
And if you're really serious (and not just sitting around waiting to be told by others where oldies likely lurk), do this: Join all the historical societies and museums in all the towns around you. Volunteer docent time. So you'd do things like man the desk, work in the archives, etc..... Get to know the folks on a first name basis. And you would be surprised what doors that opens up. I work at 2 such museums/societies, and have found great leads. And having the museum badge opens up credibility to get into sites. You flash that when you show up at a private property site, saying 'Hi, I work at such & such, and I'm doing research for an article I'm writing about the site of the supposed stage stop said to exist on the back-40 of your ranch here. Is it possible I can go take some pixs ?" And you regale them with your knowledge and interest in their family stuff. That morphs into md'ing, etc....
Yes I know that takes years of grooming and time. But at a minimum, hit the history books. My favorite is stage stops and immigrant stop/camp spots and defunct country picnic sites/resorts/springs. Of 15 or 20 spots you research and check, perhaps only 1 will pan out. Typically the spots are now under a modern home. Or under a freeway or shopping mall. Or have been hunted to death already (if they were 'no secret to the history books'), or are gussied up modern tourist traps, etc.... But once in awhile you find the gem where all h*ck breaks loose and you score on a plethora of classic finds and signals.
You're also not far from the southern end of the gold rush chain of events. If you can find out where longer-lived tent city zones existed for those, they can be fun. DON'T get lulled into "rushing to the ground zero of remaining evidential foundations" . Those might be nothing but the processing/industrial stuff that remains to be seen. And were just work zones, not "living" zones. You want to go where the camp towns were. And since those were often short-lived little tent city zones, perhaps nothing remains to be seen on the landscape now. And they might be quite a distance from the mine-shaft openings themselves. They typical md'r rushes right to the shaft openings, or the stamp-mills etc... (since those are what we currently see as "remains"). When in reality, it's the places that the miners ate, slept, drank, and played that you want to md.