I took these pictures during a recent course in Ouray, Colorado, where we practice making different types of anchors on ice. Note that these are all on water ice, not glacier ice. The two are different at times in character, but we use the same principals for anchors.
Step 1: Find a safe location with bomber ice.
Ice climbers send down some shrapnel! Make sure that you're out of the way to avoid getting hit. This usually means going to the side of an ice flow or hunkering down under an overhang.
Step 2: Find good quality ice for anchor.
Good ice is not fractured, hollow, or aerated, and is attached to whatever it's on (usually rock). It's a little difficult to describe exactly, but this part is fairly intuitive.
Step 3: Place the first screw.
Locate a place that the ice is fairly flat. If there are any protruding points of ice, feel free to use the adze or pick of your ice tool to knock them out to make the surface smooth. You'll want about a 10-inch diameter to allow the ice screw to rotate completely around. The angle of the screw should be roughly perpendicular to the surface of the ice. If anything, have it go just slightly (less than 10-degrees) downward. Drive the screw on home!
I usually use wire-gate non-locking biners.
Step 5: Clip your anchor material to each biner.
You can use a double-length (48") sling, which seems to be the perfect length for ice anchors. You can, of course, use a cordelette, or triple-length sling as well.
Step 7: Attach your lockers, and belay on!
See Part 2 to see ways to make ice anchors on more complex terrain.
--Mike Pond, Instructor and Guide