Sticky swatches, patterns, gradients, brushes and symbols.
I get so very tired of having to re-create what I've made or added earlier, or find the original file that contains things I've created earlier. It's starting from zero every time I open a new file.
It would be so nice to have things I added to panels be there for the next file.
There are several options to make resources sticky.
1. Save your swatches/brushes/etc. library as user defined one on a disk, using the dedicated panel’s menu. Open each then from same menu in User Defined sub-folder. When the separate palette appears, mark is as Persistent in this panel’s menu, This will make these palettes stick after Illustrator relaunches.
2. You can locate document profiles (Print.ai, Web.ai, etc.) on your machine (in New Document Profiles folder), edit their predefined presets, and resave them. This will make every new document based on these profile to have your resources.
3. Save a current document with the resources as a template, and later call them File > New from template. This will fixate the artboards settings though, unlike method 2.
But be careful with methods, because Ai can reset document profiles when updates.