Use reward programs - check out such products as Swagbucks and Shopkick, these companies will give you special discounts and gifts for filling out surveys and shopping around.
Contact customer service - many times by chatting with a customer service representative they will give you extra discounts to complete your purchase.
Set up discount email - to clean things up, set up an email specifically for collecting coupons and discounts without cluttering your personal email.
Avoid dynamic pricing traps - clear browsing history and logout of social media accounts to avoid being targeted with higher prices.
Free Shipping - always look for free shipping coupon codes or for the minimum free shipping amounts to score this discount.