One way to avoid copy - lawsuits is to make unique designs and have molds made for mass production. examples:
Of course, you'll want to know which type of angler you're supplying with lures:bass, panfish, muskie, walleye, striper, etc.
Lure sizes and shapes depend on the species targeted. Many anglers hold their noses when I mention small lures for large fish though I know they catch fish.
Advertising and reaching potential customers is a challenge. Even getting anglers to use free samples is difficult when trying to get them to use something other than proven lures they have confidence it.
Shipping costs affect sales and add to the final costs of production + consumer shipping. They are going up this week BTW. How much can you charge for a package of 10 lures taking the above into consideration? Check Amazon for examples.