Can you combine Manufacturers coupons?COUPON CLIPPERS?

I have been using coupons for a while but never serous. here is my question: can you combine manufacturers coupons if they are not exactly the same? Let me give you examples :





I have a coupon for $1 off of pepsi and one coupon for .50 off of pepsi, can I combine the two? I know you can combine Walgreens with a manufacturers coupon or a CVS with the manufacturers but can you combine two manufacturers?





This part is for more serous Coupon CLippers:


Does the combining make a difference if its P%26amp;G Manufacturers or Red Plum, Smart source? Does any of that matter? Or does it really depend on the coupon saying do not combine with any other offer-only one coupon per item purchased? I have been embarissed enough these last few days LOLCan you combine Manufacturers coupons?COUPON CLIPPERS?
1 product, 1 coupon. You can't use two coupons for the same product regardless of where you get it (red plum, coupons.com, etc).





also, some stores won't accept computer generated coupons so check first.