I came across these excellent short videos on creating beautifully-lit videos on your iPhone or webcam with only $100 worth of equipment from Home Depot. Of course, the iPhone would be the part that costs you the most but if you already have one then this really does make it look simple!
Thanks to Wistia for making the videos and Appsumo for sharing them!
Wistia provide this simple illustration to show the placement of iPhone, lights and subject (more here):
Lastly, to create a video using your webcam, here's some tips to get it looking great!
There are an exact list of equipment on Appsumo and the Wistia Blog has plenty more great tips.