This is based around how it looks on a Sense 6 phone (One M7/M8)
You of course need to start with installing the Sense home update that’s on Play store, it was called Blinkfeed before there.
Ok, that I’ve done. So, how do I select a theme? there’s just the regular 4 under Settings > Personalize?
Either long-press on empty part of regular screen and select “change or edit theme”. Or select the Themes app from all apps.
Inside the app, you can make a new theme by tapping the + sign in the upper left hand corner of the app. This starts a guide that bases the theme on your current wallpaper, and it will use colours from it. You can tap “edit” in the second step to fine-tune it as you want, or swipe down to see the different variants. When it’s all to your liking press Next, there you type name of it and just tap OK. With default settings it will be applied as well.
If you you want to download a theme, then press of the 3 bar icon on the upper left hand corner of the app, this will open up the left hand menu where you select Recommended or Themes. Simply find the theme you want to download, open it and click download. Note that this can be SLOW at times, but it does work. When it’s downloaded simply tap on Apply. And you will now have a new theme!