Merry Christmas and a happy starburst to you!
Getting a starburst in a photo is easy. Point your camera at the sun*** as it pokes out from around some object like a tree or mountain, set your aperture to f/22, move your camera around a bit until the starburst really comes out and shoot!
Different lenses give you different starbursts, depending on the number of blades in the lens and other geeky stuff I generally could care less about. I just like the effect sometimes. Throw in a little lens flare, too and I am usually quite happy.
***Shooting into the sun is not recommended by anyone with common sense, which excludes me. Following my advice may result in watering eyes, a pounding headache, hallucinations of sprights and fairies dancing across your vision, or irreversible and permanent retinal damage. In the event of a lawsuit, I recommend finding a defendant with real money. I am a nature photographer, which means I am poor and judgment-proof.