Oxygen  Living organisms need oxygen.  At a minimum, the container used should have air holes drilled every 2 inches along the top of the container and a number of air/drainage holes drilled underneath.  A catch pan can be placed under the drainage holes to catch "leachate" that can be used as compost tea (when oxygenated and added to rainwater).You will want to place a homemade bin on something like bricks to allow ventilation under the system.

Environment  Worms will need a place to work and a place to rest.  I like to set up a worm bin this way:  1)  bottom (working layer) 4-6 inches of the bin should place some moistened, half decomposed compost.  2) Add one handful of sand 3) top (resting layer) layer of 4-6 inches of  moist bedding.  The bedding can be any organic carbon source:  shredded newspaper, shredded cardboard, fall leaves, dried grass, hay or straw.  Let this mix sit for one or two weeks to let compost "cool" and to let microbes work on decomposing to provide best worm home.  The moisture level of the worm bedding should be like a wrung out sponge.

Temperature and Light  Worms prefer a dark, cool place in the range of 40-80 degrees F.