I started out finding a comfortable position and relaxing with a timer set for 15 minutes. After years of practice, I now hit REM almost immediately and wake up feeling rested without a timer in 15-20 minutes.
It's easier for your body to learn if you have a specific place (e.g. a coach), time (e.g. immediately after lunch), and position (I cross my ankles and steeple my hands on my chest). These make it feel qualitatively different from night sleeping and easier to wake up naturally.
You also want to pay attention to sound and light. I use noise-cancelling headphones at work and earplugs + white noise at home. I choose a well-lit area, preferably with natural lighting, and then cover my eyes with a cloth or sleep mask. It's easier to feel refreshed when you uncover your eyes to bright sunshine, rather than waking up in a fully dark room.
Honestly, the main challenge is feeling self-conscious when napping at work. Originally I would lock myself in a shower room or go out to my car, but I'm finally self-confident enough to sleep on a public coach.
Sleep at a desk might not be the most comfortable thing, but it's not bad at all once you're used to it. Or get a small bed around if you can. Sleep masks are surprisingly helpful, too.
Just relax and don't be upset if you cannot fall asleep fast, even if you can't fall asleep you'll find yourself more productive in the afternoon - it's like an implicit meditation. There are also times that people only actually sleep like 5 minutes out of 20, but it usually subjectively feels much longer than '5 minutes' because time feels longer when sleeping and it's very refreshing.
As time goes by it will become a habit and you'll fall asleep fast. The downside is you are likely to feel worse if you have things to do at noon and miss the nap.
IMO the best thing about taking nap at noon is it reduces the fear of sleeping too little at night because you know you can more or less take a nap and get a partial reset at noon.
Maybe I'm wrong on the causation but I feel more sleepy if I eat more carbohydrate.
> Could it also be something else, like the cooking oil used with the veggies and meat/tofu?
Anything would do, it's just simply harder to sleep with empty stomach =P
Sometimes I'd have had too much coffee or been overstimulated through work or something, I found [these tips from the military](https://www.inc.com/jessica-stillman/the-trick-soldiers-use-...) really helpful. Even now, I pretty much only need to relax my jaw and do a few rounds of 4-7-8 breathing and I can have a nap on demand!
Yes. If you have to look after an infant you too may discover how wonderful 12 minutes, or seven, of closing your eyes can be. Did I sleep? Maybe, but I definitely feel better.