The tags list in ecto seems to be a simple list of checkboxes. If you have a lot of tags, finding and selecting tags can be cumbersome. For that reason, I implemented a quick keyboard only tag selection and creation mechanism. Here's how it works:
First, open a draft window. Select the tags list by either clicking in it or tabbing to it with the tab key. The list is active if you see a light blue focus ring around it. Type the first characters of the tag you want to select. If the tag is not found and you have typed more than three characters, a new tag is created and checked. To check or uncheck an existing tag, just press return.
To give feedback on what you have typed as first characters, ecto pops up a transparent screen. It fades away when you stop typing. Pictures do wonders: