Recode if necessary so that all items are scored in the same direction
Compute the Cronbach's alpha (α) and examine the reliability analysis results (especially Cronbach's alpha if item removed) to determine the internal consistency and whether any items should be dropped
Recompute the reliability analysis after dropping any unwanted items
Note that the example involves only 10 items to measure one factor. If you have a multi-factorial measure, then examine the internal consistency for each set of items which represent a factor.