Among the rather odd but possibly effective practices you may come across one called "Two mornings in one day." Don't look for hidden or figurative meaning — take it literally. The idea is simple. You wake up early. That's your first morning. You do whatever you want in it and spend it however you like. Read, embroider, draw, run. Have a coffee, sit in the sun, put on music — your call. Then you go back to sleep. After a few hours you get your second morning, which you give to family, work and the rest of the things that are more usual for most people.
This approach is attributed to the writer Nicholson Baker, who does use two mornings instead of one. How effective it is, I leave to you to judge. I doubt it suits everyone. With such early rises you may still need a nap during the day or evening so you don't collapse by 6 or 7 p.m. I don't use this practice myself, though a few times — more by chance than design — I've had to get up early, do something and then go back to sleep to wake again a few hours later. On the whole I wouldn't say I liked it much, but I didn't find it off-putting either.