I was going to ask which is better a single jig or a double jig setup? Don't mean to try and hyjack this thread but I think the question fits in here.
I typically use double jigs when fishing vertical structure as the fish will suspend and 2 jigs at different depths will give you more of a chance to find them. Plus you don't get hung up much. I use a single jig when fishing brush because like stated above I don't like losing 2 jigs at once. As far as fish biting one or the other better. Sometimes 2 jigs fall too fast. It just depends on what they want.
When I started truly crappie fishing four years ago, I always fished with a single jig. I started about two years ago going to a double jig and haven't gone back to a single jig unless I'm using a slip bobber fishing timber (which isn't often). I too have caught many doubles and like 8upwithfishin', I like to use contrasting colors and different styles or brand of jigs to see if the fish are more inclined towards are particular color or style jig. I like the idea of being able to cover a wider span of water with two jigs.
Simply rig one jig with a loop knot and 12"- 24" down tie another jig with a loop knot. The loop knot lets the jigs act naturally and separate from each other. The distance from each lure is subjective and is used to find what depth they are at. If they hit the top lure raise your jigs a foot or two to get both jigs in the "zone". If they bite the bottom one lower you jigs to a foot or two. Easy peasy.
I do a 2nd jig when I fish bridges for many of the reasons mentioned above. I hate the 'Loop Knot' for the top jig because I have had it break many times costing me fish and two jigs so I use this instead for the top jig.
It works very well for double jig set-ups. It's the VMC Drop Shot hook and you can find them at Wally World for $3.48 for a pack of 5.