If you print your own coupons , you've probably run across the "print limit reached" message. What I've figured out is that on each site you can usually only print 2 of the same coupon at a time. Then you have to wait for however long for the coupons to reset (I haven't figured out how long yet). I have figured out how to get more than 2 coupons for those things you want to stock up on.
1. Multiple computers - If you have more than one computer in your house print the maximum allowed coupons from each computer (in my house this = 6 coupons).
2. Multiple Websites - One of the coupons I've been trying to stock up on lately is the Yoplait Frozen Smoothies. They are on sale at Kroger as part of their Frozen Foods Event for $1.99 and with the $1off coupon that is available on Coupons.com as well as the Yoplait website, that means .99 each. I have found that not only can you often find the same coupons available on Coupons.com or the other major coupon sites on the manufacterer website, but there are also often sites that use the same coupon base (ie. coupons.com) but not the same tracking cookie, allowing you to still print the coupons off of those sites, even after you've hit your limit on the others.
For Coupons.com coupons, be sure to also check http://www.couponbug.com
For Smartsource coupons, also check http://www.coolsavings.com/printablecoupons.php
Another option for coupons that you see in the paper, if you don't want to buy multiple copies of the paper to get more than one coupon, is to go to Ebay. There are many folks there who will sell you bundles of specific (or random) coupons for as low as .99 for the bundle. I just picked up 20 coupons for Marie Calendars frozen meals for just .99 on there (including shipping).