How can I block the light that gets through the outskirts of my bedroom curtains?
See image below.
Note I am renting in an apartment so I can't do anything permanent.
There are two solutions I've had success with: Get some painters tape, so it won't leave adhesive on the windows, and put a strip or two on all sides of the the window glass to darken that area and keep light from entering. The other one is to get some white masking/duct tape and add a strip on both sides of the shade to extend the size of the shade by 1/2" to 1" +- on each side. If you don't open the shade, you can also put a strip across the top when the shade's pulled down.
Get or make a wooden frame that fits snugly in the window opening. Staple to it corrugated cardboard or other opaque material cut to fit. This layer may be painted or covered with a layer of decorative cloth. Attach knobs or handles for easy installation and removal. If the window is large, use two frames hinged together.