I did a deep dive with tabs recently and experimented with making and using all kinds of tabs in my junk journals. In my mind, I separate them into functional and decorative tabs.
These tabs in my ephemera storage journal are functional because they let me know where my various colors of ephemera are.
The vellum tab on the side of the page can be either functional or decorative, depending on what label you slide into it. And the pink tab on the side of the belly band is functional because it lets you know there's a journaling card inside of the belly band.
This tab on the top of the page is also functional because it lets you know there is a fold out page attached.
And the tabs on the side of the page work as hinges for the fold out page.
This picture has a decorative tab on the top of a tag as well as decorative tabs on the side of the page. The round tab is just 2 circles glued to 2 rectangles. The top tab on the side of the page is a bit of collage attached to a paper clip, so it is removable.
This tab is just two circles: one glued to the front of a tag and
one glued to the back.
Here's a tab as a tag topper.
I hope this post gave you some good ideas. Here's a link to a video if you are interested: Junk Journaling Tabs Video