Another popular option when using round head jigs is to rig them with live bait. When it is live bait the fish are after, your fishing can be enhanced with the addition the color and attraction a round head jig provides.
One of my favorite ways to do this is rig a nightcrawler on a round head jig. Cast it out, let it sink, then every once in a while give it a tug, and reel it in a few feet. Experiment with the weight of the jig head. With the extra drag of larger live baits, the lighter jig heads will allow your bait to sink slower and provide that wiggling action on the way down.
Other ways of using round head jigs with live bait
When fishing for walleye, I usually leave a few inches of nightcrawler trailing behind the hook, but sometimes balling up the worm on the hook can be a more enticing alternative to other fish as well. Leeches are popular among smallmouth and walleye fisherman. Leeches are easily rigged to round head jigs by hooking them through the head and letting the tail do the work of swimming through the water. You can rig minnows and shad the same way you do a leach, hooking it through the mouth or lips, making sure it is facing the colored head.
Next time you are fishing live bait try a jig head and see if it changes your results.