I have been traveling quite many years now and certain things are happening every time. I pack on the last evening and almost every time, I also prepare everything on the last evening (ironing etc.).
For this kind of short European trip, I of course need to pack my suit but then I also need some other important stuff such as my Airport Express, which will help to create WLAN in my hotel room if there is only a wired Internet - hopefully there is as today most of the hotels will only allow one computer and I need connection also for my phones. Need to get online you know. :-)
Otherwise it follows the same usual path, check-in and print the boarding passes as soon as the check-in opens (try to catch boarding number 1 if possible; today I got 1 for the first flight and 2 for the second flight). Update relevant applications on the phone (make sure I have up to date itineraries with me and lounge locations etc.) and check that I have updated my music (and videos) for the iPod.
That’s it, pretty simple. Most of the stuff I take with me are always the same and some of those are already packed even between the trips. Just waiting for the next trip.