2. Different lenses will create different shapes
The lens you choose to shoot with will change the look of a sun star; also, unfortunately, the more expensive lenses do tend to produce sharper, better looking stars. Not all lenses are created equally, though. Sun stars are caused by the light passing through the small aperture and being diffracted (spread out) across the aperture blades inside the lens. The number of aperture blades in your lens will determine the number of points to your star. As well as this, the straighter the edges of the blades are, the sharper the stars will appear. It’s worth experimenting with all of your lenses to see what you prefer, but wide-angles are most common for this type of image.
3. Be creative with your positioning
The best place to position the sun in any image is where it’s just peeking out from behind an element. This could be the edge of a tree, through a gap in leaf canopy, or above a distant peak. It will still work well with the sun in the middle of the sky, but if do you move around with the camera and find that sweet spot where the sun is partly obstructed by an object… then that’s when the magic happens.