Drill bits are designed to cut specific sized holes in specific materials. Using the wrong bit for the wrong task can not only lead to less than satisfactory results. It can also damage the bit, which is some cases can be a costly mistake. The two main divisions in most common bits, such as those found in multibit tool sets, are wood boring bits and masonry, or concrete, bits. Using anything other than a masonry bit when drilling concrete, brick or stone will result in frustration and dulled, broken bits.
Lay your drill bits out on a flat surface with adequate light. Divide them into categories according to the tip shape and the style of the bit blade.
Run your thumb over the tip of the bit. Any bit with a sharp cutting edge on its tip is a wood, or multiuse bit. Look for cutaways leading down into the spiral of the bit to indicate how aggressive the bit is. Look for sharp, pointed tips and large cutaways for a quick cutting bit.
Look for an arrowhead shaped tip to indicate a hammer-drill style masonry bit. Inspect the sides of the bit's tip for fins to indicate a more aggressive cut. Be aware, these fins widen your hole, and should be measured when determining bit size.
Find a bit with a cone, or sharp bullet shaped tip to use for a standard, non-hammer rotary drill. Look for the same fins you saw on the hammer drill bit to indicate a faster cutting bit.
Use wide, flat blade bits with a point in the center for cutting larger holes in wood. Typically these bits are known as spade, or paddle bits and can range from 1/4 inch to over 1 inch.