I use hardbound notebooks . When I started out, I used wire-bound notebooks, the kind you use in class. However, the paper quality isn't particularly good and the pages rip out easily. The covers rip off. The journal begins to resemble the physics notebook you let molder underneath your bed.
Hardbound notebooks are more expensive but worth it .
When friends of mine go to Europe, I make requests for them to bring back hardbound, sewn notebooks. I date each entry . I also tend to write down the time and the place I am when writing the entry, but that's a recent innovation. If there's a cloud that isn't smog-colored, there's something odd and possibly sinister going on. I never read any part of my diary to anyone.