First of all, you should check the airlines' websites as frequently as practical to try to move to a better (more forward) seat; elites are likely to begin upgrading 6 days before the flight and this tends to open up some good seats. You can change your seats on the computer as often as you want for free. You should try to do on line check in at exactly 24 hours before the departure time so as to maximize the chances of being able to purchase a "choice" (preferred because of aisle, bulkhead, exit row, or toward the front of the aircraft) seat near the front on the first flight. If this doesn't work and you have a seat assignment that isn't good--i.e., in the back in this case--you can stop the check in and continue to monitor the website and try later, in hopes that you might get lucky with a better seat, perhaps as others are upgraded or switch to other flights. However, especially for the holiday travel period, you should certainly arrive at the airport with a printed boarding pass and some seat assignment if at all possible.

During the on line check in process and before leaving for the airport, notice your arrival and departure gates, although be warned that gate assignments do change and you will need to verify the departure gate when you arrive in DTW. When your flight arrives at DTW, try to look out a window to see the sign for the arrival gate and listen for the crew announcement of the gate before landing but verify that your plane really did arrive at the planned gate in DTW. Look at the online airport terminal maps and familiarize yourself with the airport's layout and gate locations before your travel day.

Also, think/plan to run through the airport if necessary. Do you want to check luggage (and risk its failure to arrive on your flight) in order to be able to deplane more easily and run faster through the airport? You should ask if this is still true, but at one time gate checked bags--what will happen to any carry-on that won't fit into the bins on the plane--were checked only to the connecting airport, where the passengers needed to wait to retrieve them outside of security before boarding the next flight. You will not make the connection if you must go to baggage claim in DTW, so you might not want to risk the possibility of being forced to gate check a bag. This means that you either pay to check it at the first airport, really minimize what you take so that it all fits under the seat in front of you, or try hard to board your first flight as early as possible (but after first class and elites have boarded), so that you must be at the gate before boarding begins for your first flight.

Within DTW, and especially within the A concourse areas, wheeled luggage works well on the moving walkways which are extremely wide and also on the escalators to and from the little airport train that runs the length of the A concourse with three stops every few minutes. Don't take anything that will slow you down!

A potential disadvantage of my suggested strategy is that, as a nonelite, you are likely to pay a baggage check fee (no refunds if the bag doesn't arrive on your flight and no compensation for the inconvenience) and an additional fee for choice seating on the first flight. Consider whether it is worth paying this to (hopefully) lower the chances of missing your connection balanced against what will happen if you miss the second flight. Maybe the cheap ticket isn't really so inexpensive in the end.