Method of and apparatus for indexing a workpiece to a tool at a predetermined angle of orientation, using a bubble level to establish a horizontal reference plane. The bubble level may be pivotally fixed to a housing of a jig which may incorporate a magnet for adhering the housing to a magnetically responsive workpiece. The bubble level may be secured at a particular pivotal orientation such that when the workpiece is held against the cutting or abrading surface of a tool, the workpiece may be manually maintained at the predetermined angle of orientation such that a ground surface disposed at a predetermined angle on the workpiece may be formed while holding the workpiece manually. The jig may incorporate an adjustable leg to assist in tightening the bubble level at the particular pivotal orientation.