Here are some great instructional videos on using lure making kits to create your own lures.
This first one features legendary fisherman Larry Dahlberg and covers making soft plastic lures and hard baits.
In the video, they show how to create a big soft plastic and a big hard body to target musky using a lure making kit.
The second video covers soft plastics alone while the third introduces a spinner bait bass lure making kit.
Lure Making Kits
This next one is solely on soft plastics but goes into a lot of detail about using lure making kits to create wonderful soft baits.