I have trouble sleeping when it’s light. In the summer, I’ll wake up at 5:00 AM when the sun comes up. We’ve tried many things to block out the light. Special light blocking curtains, etc. But none of them really worked well. We also didn’t get the special shades that are “guaranteed” to work, since they cost a few hundred and we didn’t want to get burned again. But we found something that worked. Here’s our room with just the normal curtain.
Now it may not seem like a lot of light to some people, but it really bothers me in the morning (plus it was slightly overcast outside when I took this picture). So what I did is take a curtain rod and put it on the inside of the window frame and hold the curtain into the frame. Like so: