An example of some wonderful kits from a place called Second Story Online, which no longer exists as far as I can tell. She opened a store in the Dallas Texas area, but now I can not find a listing for it.
Her kits taught me a lot of the stitches and techniques that I use today.
Kits are a great way to try out more complicated techniques and to become proficient in stitches you might be new to. You can focus your attention on learning, instead of creating with form and color. That has been done for you in a kit.
When you feel you have mastered what you were attempting to learn, then branch out and apply the new skills to your own designs. The Garden Trellis (top left) is a little glass bottle covered in netting. It was the starting point for a series of pieces I did, an example is the Teal & Purple Bottle Necklace, in which I explored the form of the vessel, but, without the vessel.