Keep them frozen until you use them. This is my method, but you might find a different and better one that works for you---then share it!
While they are frozen I whack the bag a few times with a tenderizer hammer to break the block into small pieces. I put the main bag into a Ziploc and then into a plastic shopping bag (I don't want any contamination of BW into my human frozen food!--I'm a nurse!) Then when I'm ready to feed them I take out as many chunks as I need and put them in a bathroom size Dixie cup with very little water--just enough to defrost the worms. Then I use a toothpick to scoop them out and drop them into the tank. I tried a cone feeder, but my frogs don't go for that, so I just drop and let them sink. If you are feeding frogs and fish, make sure you put enough that the frogs will get some. They aren't the quickest hunters of food, but once they smell it they are good to go. Sometimes I will drop BW and wait 15-20 mins so the frogs start to smell them and then I'll add fish flakes for the others. Otherwise, the frogs smell the flakes and not the worms and your left with lots of uneaten worms. The papercup and toothpick are just cheap and easy and I don't have to touch or clean anything.
GOOD LUCK!
-M