As a current student, I can relay some of the things my parents did that proved helpful to me. During the year before I started school, I gradually took on many of the responsibilities previously held by my parents: laundry, cooking, appointments, etc. Doing these things at home was great because I not only learned the necessarily skills for independent living, but I also had the rest of my household to fall back on if I made a mistake. By the time I left in August, I had no problem managing things by myself, since it had become a routine when I still felt comfortable at home.
Similarly, I was responsible for a lot of my dorm shopping–not only in the actual purchasing, but in list-making as well. I researched my dorm room and made sure that I got everything that I needed, so I felt more in control of my situation when I actually unpacked during move-in. On that note, my parents also made sure to leave fairly early on move-in day to let me settle myself into my dorm room. Don’t get me wrong; they helped me unload the car and put together heavy objects, but I was the one to unpack everything and set up the room. It was definitely hard for my mom, but I think it was a good idea. It forced me to socialize with my new hallmates rather than hanging out with my parents for the rest of the day.
As several people have mentioned, I also find it comforting to have a set time to call/skype my parents every week. I think I called home a lot less for little things because I knew that I would be talking with them later in the week.
Other than that, I’ll second the common advice of reading the syllabus, early starts, office hours, electronic calendars, etc. I personally use a spreadsheet to keep track of my homework, since it allows me to sort by deadlines and keep track of assignment details–but if you(r child) prefer(s) another method, that’s fine. As long as you make an honest effort to complete every assignment, you should see the results you deserve.
Edit: Also, if applicable, take any AP exams you can. I know so many people who took an AP class but didn’t take the exam because they didn’t think it would matter in the long run (spoiler: it might). Having transfer credits gives you so much scheduling freedom, so unless none of the colleges you’re applying to accept the credit, take the exam.