For most people simply looking for help making holes for hanging picture frames, repairing damaged furniture, or completing a few fun DIY projects around the home, a set of general purpose drill bits makes perfect...
For most people simply looking for help making holes for hanging picture frames, repairing damaged furniture, or completing a few fun DIY projects around the home, a set of general purpose drill bits makes perfect sense. As long as you will only be drilling into wood, drywall, or composite materials like MDF (medium density fiberboard, a material commonly used in lower-cost shelving and furniture), then a basic set of twist drill bits, those with a spiral shape along their shaft, will get the job done with aplomb.
For more complex projects involving harder materials, you absolutely must use a specialized drill bit. Try to send a spiral drill bit into a piece of tile, for example, and you will crack the tile into pieces. Try to use a twist drill bit on a thicker piece of metal, and you will waste your afternoon, and likely ruin the bit at the same time.
While a set containing lots of different varieties of drills bit might seem like a great idea, if you're never going to drill through sheet metal or glass, there's no need to look for bits capable of so doing. Instead buy a set that meets your current needs with bits in a range of sizes (starting with a narrow bit and working a hole wider and wider is the best way to go, after all) and then consider adding a single specialty bit later if needed for a specific purpose.