farmers that breed those giant contest pumpkins will pollinate by hand the flower, then they close the petals up over the pistil and tie with a rubber band. I bet a paper bag would work just as well. I wouldn't really worry about wind pollinated like stated above but more so the bees going from all the different flowers in the areas of your yard.
I love poppies!! my great grandma had the old 1920's red oriental poppies. tried to transplant but that didn't go over so well. I didn't know about the pods until after the house was sold