For through-drilling, clamp the work piece to a support (e.g., leftover piece) and simply drill through the work piece and into the support. This will prevent tear-out on the underside of the work piece.
Guiding the drill bit
Drilling with a pillar-type drill helps to drill precise holes and keeps the drill bit linear. Drilling with a hand drill requires a steady hand.
Removing chips when drilling
While drilling, withdraw the tool from the drill hole regularly to remove the chips from the flute. If it is not aired and the chips are not removed, the flute will become blocked and the drill bit will jam and cause burnout.
The drill bits will stay sharp for a long time when used carefully and properly. It is important only to use the tools in solid wood or derived timber products. Metal or stone will blunt the tool or break the cutting edges.