i feed my BPs every saturday
they all get a rat, the size of which depends on the size of the BP
i give the rat a little knock on the head to stun it (might seem a bit cruel, but i've had rats bite several of my snakes in the past, including one bite that got infected and required a visit to the vet), then drop it in
i prefer to put them one at a time in a seperate 40 gal plastic tub with no substrate, but a few are picky and will not eat unless they are inside their own enclosure
i just bought 4 new BPs, and they are a bit smaller, so i may feed them twice a week until they hit 300g or so