Tinted moisturiser in the morning if you look a bit tired and pasty. I use the Dermalogica one, which is a little pricey, but lasts for ages. Find the Nivea one a bit "thick", but I'm sure there are better reasonably priced ones if that's an issue.
Agree that mascara is a must. You look instantly less tired.
A good, soft brown eyeliner is very useful (if you have pale to medium skin). There's a Loreal pen-style one (as opposed to the kind you sharpen). A line of brown eyeliner along your top lid can open up your eyes, doesn't look too "done" because it's soft pencil, not a harsh line. Black works if you have darker skin, of course.
Lipgloss, even some sort of lip moisturiser. Brush flakes of skin off your lips with your toothbrush.
For the summer, it's a must to use a pumice or foot scrubber thingy on your feet and heels. Dry, flaky skin in sandals is a bit grim IMO.
None of that takes much time...