We used a dark purple aisle runner for our wedding. It has been collecting dust in our basement while we tried to figure out something to do with it for the past (almost) 5 years.
We found it!
The shades in Sam's room were letting in too much light at bedtime, now that the time change has extended daylight hours longer into the evening. We cut up the aisle runner and hung it over the current window shades to block out the light. It's not pretty, but we will see tonight if it does the job.
Some of the blackout shades on the market, completely cover the window and have to be completely removed to see out, while our solution can be moved aside during daylight hours to let light in, if he wants to play in his room.
We just put it up this morning, so I'll see how it works tonight and report on it tomorrow.