I drain from my kettle into bucket primary fermenters. I prop a sanitized FINE mesh, handled kitchen strainer over the bucket and runoff through that. I like catching the pellet hop debris and break material without immersing a strainer bag in the final wort, so none of the finest particles will permeate into the wort as I figure would happen with the bag immersed in the wort. But, other than waiting awhile for everything to settle to the bottom of the keggle after chilling and removing the immersion chiller, I don't otherwise have a mechanism to strain out break material so I'm just hoping to be as efficient as possible about keeping it out of the fermenter. I just keep a garbage pail nearby to shake out debris every once in awhile from the strainer as it fills with crud. This is also helpful if I decide to strain all the liquid from my kettle, by taking out the last 1/2 gallon a cup at a time.