Just my two cents but my pods rarely make it to the brown stage before dropping seeds. When I lived down South I could look for brown pods but up here the pods start to open well before turning brown. Each day I go out and look at my pods to see if they are opening. If so, I pick them. I may also try the squeeze method mentioned by Natalie!
Also, if you find a green pod on the ground always check it to see if the seeds are ripe. If the pod has been knocked off by me the tag will still be there and I can figure out my chances of getting ripe seeds. But if a squirrel has been nibbling (or throwing half-eaten apples into my daylily bed thereby knocking off pods) the tag may be gone. So before I just sigh & toss it into the compost I check it. More often than not I find (some) ripe seeds.
