I only have my inbuilt flash to work with. That does not mean one cannot get creative. So the other night I got out my camera, some plastic bags and started experimenting. First I took a picture of myself w/o flash setting the white balance to tungsten light. As you can see, my ceiling light makes bad lighting for portraits, my face is in shadow.
With the inbuilt flash alone, there are hard shadows (look under my chin) and reflection from my glasses.Not really a good portrait.
Then I took the white plastic bag, blew it op and put it around the inbuilt flash. Viola, instant diffuser.
My portrait is now much better, the light is softer and more equal
But of course I did not stop there! I got the blue plastic bag and took a picture of it, using it to set custom white balance
Basically I told my camera that the blue of the bag is actually neutral grey, so when I took a picture with the setting everything had a red tinge
Now I set up my camera with the blue plastic bag as a diffuser (it was bigger and thicker than the white one and really hard
to blow up)
Now my portrait has normal light while the background is red. Not really interesting with my closet as the background, but a proof of concept for now. I'm going to collect a lot of plastic bags and find a nice spot outside.