Paperblank's bookmarks are really beautiful! The motifs usually have a historical source of inspiration and are really nice to use in reading books.
You can find nice ones with magnets from Peter Pauper. You simply fold these over onto the page you want to mark.
From Midori there are super cute little bookmarks and these have little stencils on them. Above all, they are adorable and pretty, nice marking.
If you are looking for a smart solution to mark where you are in notebooks, you can take a look at a smart little ruler with clip from Hightide. Midori also has a similar ruler but it also has a stencil function. Really pretty!
From the Traveler's Company there is a series in brass where stencils with numbers or letters are combined with bookmarks. These are robust stories that become more beautiful the more they are used.
Ruler, stencil and bookmark from Peter Pauper are great in a Bullet Journal!
