I've been coming across various articles about napping which made me curious to try it. The one thing I couldn't figure out though, was whether it's worth it to get less sleep at night in exchange for taking a nap during the day. Having tried that for a few weeks now, I can tell you that it is. I've been getting up 35 minutes earlier than I used to, so that in the afternoon I can walk home, take a 20 minute nap, and get back to work. Before my afternoon nap I would often run out of energy between 3 and 4pm, just not getting much work done, and having difficulty focusing. Now with a nap (usually around 2:30), that almost never happens.
As in the napping article, I find that I don't need to fall all the way asleep to get the benefit of the nap. I do get in bed and completely horizontal, but usually I just doze lightly. Sometimes it feels like my alarm wakes me up after 20 minutes, but other times I don't feel like I slept. I still feel better afterwards. I do make it a point to not lie down thinking about something. I consciously go with whatever images my brain brings up, which is usually a confusing jumble like in a music video.
When napping, I always wear a Lights Out sleep mask, just as an extra way of blocking out the world. It's comfy and just works really well. Once we get some heavy curtains over the outside door, I might stop using it. Probably not though.