Workbench Community Input

So I've finally etched out a 5' X 2' space to put a workbench that I would like to make. I'm not even 100% sure of the design style yet (Nicholson, Ruobo, Anarchist, blah blah). It will probably be relatively basic, being my first self-made bench. My question is: what types of things or alterations might you make sure to include? Any regrets that you may have had with your first benches that you would have changed? I do have a running list of things I know that I want (vice, T Track or Dog holes, leveling casters). I'm not looking for every accessory known to man...rather, again, ideas or cautions from your experiences. Could even be things you regretted adding to it or putting on it in the first place.