Thank you for mention my collection!
I would like to see collections about functions or tools of PeakD, as well as another interfaces such as wallet.hive.blog, leofinance, etc.
Collections about science, math, engineering, technology (STEM).
Collections about different sports, such as F1, baseball, football, etc.
I create STEM and sports content, so I may create some collections of that soon.
You can put literally anything in a collection, I'm sure many other creative ideas will come up.