Use plastic clamps or metal C-clamps. Tighten the clamp or vice to your workbench so the metal is secure and will not move while you try to drill. If the clamp is loose, the metal could spin while you drill it and cause you harm.  If you’re working with a heavier piece of steel, you do not have to clamp it down. If you’re drilling through a painted surface, put stir sticks or shims between the clamp and your piece of steel so the clamps don’t dent or scratch the metal. Measure out where you want to place the hole in the steel. Take the diameter of the drill bit into consideration when you place your hole. Make a dot on the steel with a pencil to mark where the location of the hole’s center. Use a permanent marker if pencil doesn’t show up on the steel. Place the tip of the center punch on the mark you’ve drawn on the steel. Use a hammer to tap the punch slightly to make a small dent. This helps keep your drill in the right spot rather than it moving around while you try to make the hole. Use a nail if you don’t have a center punch.
Clamp the steel to your work surface if it’s lightweight. Mark the spot you want to drill with a pencil. Make a divot in the steel with a hammer and center punch.