Tags Are Ordered
Most POD platforms only accept a limited number of tags, some as few as 10. To ensure your designs are published with the most relevant tags, you should prioritize your tags. Furthermore one platform (TeePublic) treats the first listed tag in OrbitKit as a special "main" tag.
Each design has its own independent list of tags and tag order.
Tags Can Be Private
Tags that start with $ are private to you - they are not published to POD platforms. Adding and removing private tags will not trigger exhibit updates. Their order is irrelevant.
Tags Can Be Favorites
Drag tags from your designs or the Tags page onto the sidebar to save them as "favorite" tags. Click on them to select those designs. Drag them off the sidebar if you don't want them anymore.
Tags Change When Published
To make searching within OrbitKit easier, tags in OrbitKit are always lowercase and use dashes instead of whitespace. So you might have tags like cat-lover and dog-lover. When published to POD platforms, OrbitKit automatically converts these to cat lover and dog lover.
Don't Put Product Names In Tags
Some sellers try to cram product names into tags, eg grandpa-shirt, grandpa-iphone-case, etc. This is a bad idea for several reasons:
Your design will be put on many products, including things that are not shirts and phone cases. The tags will be wrong.
Platforms universally dislike this kind of tag spam.
Some platforms (notably Redbubble) silently drop spammy tags. If you put 'shirt' in your top N tags (where N is the max tags allowed by the platform), your products will be published with no tags whatsoever.
There doesn't appear to be any concrete evidence that this sort of search engine gaming actually works.
Bulk Editing
Don't forget to check out CSV metadata import! You can edit your name, description, and tags of your designs using a spreadsheet on your desktop. When you submit this CSV file, OrbitKit will update its database.