Some time ago I started a thread on interesting bokeh shapes (like squares, stars, triangles etc.) but because of my focus on vintage lenses - some of which show those in their original state - I didn't think of including other interesting possibilities of playing around with it, which might be more widely available and fun to try. So I want to start another attempt at inviting everybody here to
a.) share their shots of any kinds of experimenting with light (like interesting or unusual bokeh, flare, light painting, camera movement, veiling or other interesting lens defects etc.)
b.) perhaps share some background information or techniques how the effects were achieved and
c.) go out and try some of those things yourself.
It doesn't matter if you're shots are intentional or accidents and if you can't even explain what happened in your image (that happens to me regularly) it's fine as well.
Here are a couple of examples to give you an idea. I'm sure you have lots more, so please help me get this thing started as a visual celebration of light!
Playing with light by simple.joy, on Flickr
Of course bokeh bubbles aren't that special, but it can be a lot of fun implementing them into an image, because of their clearly defined shape.
Usually that's how well I fit in... by simple.joy, on Flickr
Unusual bokeh shapes are not that common, but while there are some industrial lenses with squares, stars, triangles out there, they also can be achieved by other methods. @TomAxford has shown a number of them already in this post.
Don't fret! Go where inspiration leads you. by simple.joy, on Flickr
Some people are true masters at light painting... While I'm clearly not, I enjoy making little experiments like this from time to time with a tiny light. (I think this was just the tiny LED on some kind of charger or pen...)
Forgetful angel? by simple.joy, on Flickr
This clearly shows that this lens was not made to be used outside... because it hasn't got any kind of lens hood or effective protection from stray light as a whole, this old USSR repro lens is a perfect candidate for experiments with flare.
Ghostberries by simple.joy, on Flickr
Even when the bokeh highlights of a lens aren't very distinct or special, they can be implemented into an image in unusual ways, if you're experimenting with the light and distance to subjects.