@PinkElephant's solution is great (thank you), but it's a bit cumbersome. I would really use a "sync now" button (or better, keyboard command). I recently forwarded an email to evernote that I needed to start using immediately, and the only way I could do that was to restart the desktop app. Frustrating.
As an aside, I barely use the mobile app at all, so mobile solutions are not going to work for me.