If the anthers are not open on a bloom when you want to use it, maybe it's in the shade or just isn't open yet, you can take the whole bloom (if it's not one you plan to pollenate) and lay it where the sun is and it will open faster. If the bloom isn't open just tear away the petals to expose the stamens. If it's one you plan to pollenate then you can remove just a stamen or two and lay them in the sun. I have seen people take a pocket knife and cut slightly into and around the base of the bloom and them pull it off and it leaves the pistil intake to be pollenated.