(And why Pluto's one of them!)

When it comes to staying indoors, you want to keep comfy, and a guiding principle that helps inform your purchases should be the comfort principle.

The principle, generally: You spend the most money on the things you spend the most time with. For example, you spend about a third of your life sleeping, which means you should put a non-trivial sum towards a good mattress and a pillow. Lifehacker goes much more in depth with the idea, including where you should limit the application of the principle. After all, just because you spend so much time driving means you shouldn't splurge on a Rolls-Royce, right…?

So with the principle in mind, here are a few products we recommend for the thing you spend a third of life doing—sleeping. Just one modification to the application of the principle—a hundred dollar limit, which doesn’t account for tax and shipping. Finally, we’re not endorsing any particular brand (until the last one…)—we just want to help you get a good night’s sleep and to wake up refreshed. That’s something literally all of us can use, so let’s get to it!

1. Wake-up light

Light or the absence of it is a big influence on how alert you are. Darkness is important for a good night’s sleep, and light early in the morning stimulates your body and mind. For most of us, we wake early to our phones blaring what sounds like sirens of war. It’s annoying, so here’s an alternative—a wake-up light. It can function like a typical alarm clock if you want it to, but the unique function is a bright light that accompanies it, simulating a rising sun that your body can react to. You could pay a lot for one of these, but there are sub-100 dollar options as well.

2. Blackout curtains

In conjunction with a wake-up light, blackout curtains give you full control over when light enters and leaves your bedroom. They’ll totally block out sunlight. If you’ve never used one in your home, chances are you’ve used them in hotels, where they are seemingly standard. They’re plenty affordable, sitting at anywhere between $20 to $40.

3. Sleep Headphones

Unlike typical headphones or earphones, these wrap around your head like a headband. That’s a big plus for side sleepers who don’t have to fear crushing their headphone cans. Wrap these on, play relaxing music or calming sounds to get you to bed sooner. The audio quality won’t match a quality pair of headphones, but for some light listening, it’ll do the trick. Plus, it can work as a music player when you’re out on the run. You can check out Lavince’s headbands.

4. Pluto Pillow

You’re spending time and money customizing your bedroom for optimal sleep, so customizing your pillow is a natural corollary. We set out to solve a simple problem—finding the right pillow—and we think our solution will work for you. Custom pillows built to how you sleep and what you like. We think you’ll love it. At $85, with free shipping, the only other cost you’ll have to factor in is taxes.