Parallel De-barbing:

Many fishermen and fly tyers prefer this method because the hook "spear" (the straight portion between the point and bend) is fully supported by one jaw of the pliers, minimizing the risk of fracturing or breaking the hook. Moreover, the barb is forced both downward and toward the hook bend-a direction precisely opposite to that in which the barb was cut. Advocates believe that pressure of this type lays the barb down flattest (particularly on larger hooks) and produces the least stress on the hook spear. This method, however, can be tricky with small hooks, which are difficult to handle and require a very fine-tipped pliers.

Perpendicular De-barbing:

This is the most common technique, though the risk of breaking or worse yet, fracturing a hook that may break later, is increased. And because the barb may break off or curl rather lay flat, the results are sometimes questionable.