Try before you buy - Get samples from your doctor first.
Opt for generics
Check out government programs - If you're on medicaid or medicare there may be programs to help you.
Consider over-the-counter drugs - Ask your doctor if over the counter drugs will work just as well. When I had minor surgery I found that Aleve worked way better than the drugs that I got through the pharmacy. Big waste of money!
Ask your doctor about pill splitting - Buy pills in larger amounts and cut them in half.
Order by mail - Be careful with this, there are some shady companies out there. But if you can find a legit one, it's gold!
Look into patient assistance programs
Buy from a wholesale club - Wal-mart is notorious for have a cheap prescription drug program. Also look at say Sam's and Costco to see what they offer.
Shop local and ask - This in my opinion is the most unexploited tip. Just like getting estimates for tree work, get prices for prescription drugs. Call the big companies and also call your local small town pharmacist. The difference in cost will shock you!