Frankly I'm surprised this feature hasn't been implemented. With the way Evernote is designed to organize your thoughts through lists of notes and stacks of notebooks, pinning a note or a notebook from time to time so it's always on top is intuitive to me. I know there are workarounds with shortcuts and saved searches and such - believe me I've spent a lot of time learning Evernote features through blogs, support forums, and experimentation since 2011 - but there are times when pinning as described in this thread is simply better for the task at hand.
About 98% of the information I captur