Here are two photography hacks which use a simple white tshirt to improve the lighting of your photos. They come from Darren Rowse of Digital Photography School.
In situations where you can't use a reflector (and for minimising the set up needed) you can wear a white tshirt to reflect light onto the subject. You'll need to ensure you're standing close enough for the light to reflect.
And the other tip? When shooting with a flash you can diffuse its impact by bouncing the flash off yourself. This way the subject is lit indirectly, but with a white natural light.
Thanks for the tips, Darren!
DIY Reflector - Wear a White T-Shirt [Digital Photography School]