Time it right. Unlike the Southern states, your window for planning an enjoyable outdoor trip to Northern Ohio is short. Cedar Point reports its slowest months as May, June, and September. Taking weather into account, early June is an excellent time to go.
Go during the week. If you're a true coaster fanatic, it's worth taking a couple days off work. On a Saturday in July, you'll be lucky to ride three coasters the entire day. Ideally, plan to spend two days at the park, or possibly one evening and one full day.
Stay at one of the park's resorts, which extend to their guests the opportunity to enter the park one hour earlier than the general public. You can also take advantage of the courtesy shuttle. The historic Hotel Breakers in particular is an excellent choice, just a two minute walk from the park and offering its own beach on Lake Erie.
Map it out before you go. Decide which rides you cannot miss, and even if you're more of an "ease into it" type, start with the biggest. If you have your heart set on the Millenium Force, you'll be glad you stood in the 45-minute line first thing in the morning once you see that it's at three hours the rest of the day.
Adopt a zero tolerance policy toward chickens, yourself included. If your mother has always been a 'fraidy cat, that's one thing, but if your gung-ho coaster companion suddenly becomes faint at the sight of the Magnum (which is NOT the tallest coaster in the park), don't let them back down. They'll thank you later.
Practice the art of distraction. Whether it's for your terrified twelve-year-old or your terrified self, call the Millenium Force ascent an opportunity to get a magnificent view of the lake. Engage your riding partner in deep conversation while in line for the Top Thrill Dragster, lest you witness the cars miss clearing the peak, necessitating a second terrifying launch.
Be patient. Even during the week, lines for the major rides will get long. Wear comfy shoes, and bring your good attitude.