My camera came with butterfly lens hood, and I've seen pictures of the cone shaped hoods. What's the difference between the two shapes? Also, how often does everyone use their lens hood? Is it just for when the sun is out and in front of the camera? Thanks for any tips.

I use mine all the time.It protects the lens, and keeps out unwanted light sources. If you have a built in flash and need to use that, Take it off or it will cast a shadow. I also am guessing, but think the butterfly shape allows just enough light in without any vignette a solid one may cause.

Attached Link: Lens hoods DIY

Doug is right, the butterfly hoods help prevent vignetting (darkening of the edges of the frame) Most hoods for wide-short telephoto lenses are of the butterfly type, as these offer the best performance in that range, longer lenses usually have a solid hood without fins, as the narrow angle of view doesnt cause the issues with light drop off at the edges that that can be associated with wide lenses. I use a hood always, unless it is not possible because of obstacles. Richard posted a link for DIY lens hoods, which may help if you have lenses without hoods.

And here I wasn't even using mine at all. Thanks for the tips everyone.

If your hood causes vignetting you should throw it away and get a hood designed specifically for your lens. There is no excuse for it to get in the field of view. My zoom lenses have hoods that correspond to their wide settings so they don't cause vignetting.