1. onlyto:me is:unread: This search shows waves that are directed only to me (no one else) and are unread. It provides a much more streamlined view of incoming waves that I'm more likely to want/need to respond to because they're only to me.
2. creator:me -is:note: These are waves I have created and added other people to, which most likely means they're waves I'm waiting for responses on. This view is very similar to an email sent box.
3. is:note: I've taken to using Wave as a personal notebook, and jotting waves that no one else is a participant on. This is probably an outside use case of Wave--its purpose is collaboration--but this handy is:note operator does easily return "notes to self" waves.

To save a search, enter the query, and then press the "Save search" button on the bottom righthand side of the results panel. As you can see in the screenshot, I also like adding a little color to my saved searches. To do the same, click the drop-down button next to a saved search and choose "Set color." What Wave searches have you saved?