Check with AARP, AAA and even your own employer may offer super-reduced admission tickets. Get in touch with your organization to see what deals are offered.
Look for promotional coupons stacked at the end of the checkout counter at your local supermarket
Read the label of your soda can, not just for the calorie content but for seasonal theme park promotion discounts.
Eat more fast food. Like the soda sellers, junk food purveyors also team up with theme parks to offer discounts to their mutual customers.
Check directly with the theme parks. For example, Disney parks offer free admission on your birthday, and Universal theme parks offer reduced admission prices during the first nights of Halloween Horror Nights.
Be suspicious of online discount brokers. They may send you authentic looking tickets at a handsome price, but they're often counterfeit.