If you are on site take advantage of EMH. Get there right at EMH opening. This gives you the extra hour for resort guests plus about an hour of regular opening time before the parks start getting crowded.
Also, evenings and night time end to have shorter lines as parents with young children leave the park. It seems the most crowded time is from about 11:00 am to about 5:00 pm.
Parade times are good to squeeze in a few rides. Also, stay away from attractions near the "show" (like Philarmagic) when they let out as large crowds exit and start looking for the nearest rides.
Eat meals at off hours. People often break for lunch between 12:00 and 2:00. Keep touring at this time as the lines will be SLIGHTLY shorter.
Use the single rider lines at the few attractions that have them.