Quality finds come from quailty time at quality locations. No matter how much time you spend at a site, you aren't going to find silver if it isn't there. No matter how much silver is there, you're not goibng to find it if you don't spend time looking. Spend enough time at sites likely to produce, and you *will* find the silver.
A case study - I found a total of 3 silver coins last year, but a bunch of silver and gold jewelry. I spent a lot of time hunting modern parks. This year I'm at 9 silver coins this year, but only 1 gold and much less silver jewelry. Reason being? I've found older sites more likely to produce silver coins, and neglected the totlots. I've also beaten last years oldest coin by about 100 years, and have many more amazing relics to show for my work, too. My personal best has been 2 silver dimes and 1 silver ring in a single hunt, but motly they come one at a time. Some people will have amazing honeyholes and pull 3-4 or more silver coins a hunt for a while, but they all eventually dry up. Those are the good days, and we all have them, but cherish them as they can be fleeting.
Don't like what you're finding? Find a quality site and spend some quality time there! Good luck and happy hunting!