Parking at Ogwen cottage, north end of Ogwen valley.
Follow path to Cwm Idwal, then head along track, past Idwal slabs towards Devil's Kitchen. South Gully is the obvious line above.
First pitch is 10m or so of 65 degree ice. Belay on wall to left at top. Then move up to a belay to the right of the main pitch. Climb ice up bearing left, to a belay above on the right. Choice of line for one more pitch, before broken ground leads to the top.
Rope, ice axes, helmet, slings, three or four screws.