It is best to use a quickdraw or runner when clipping protection. This reduces rope drag and decreases the chance of the rope's upward travel dislodging your protection. Make sure the carabiner clipped to the protection has a straight-gate design. This reduces the chance of cross loading or of having the rope flip across the gate and unclip itself. Never clip the rope into fixed equipment with a single non-locking carabiner.
Modern sport climbing often involves taking numerous short falls before achieving success.
Although impact loads generated in these falls aren't necessarily high, repeated falls cause equipment to wear out quickly. This wear is particularly visible in climbing gyms that use aluminum, vs. steel, carabiners. These softer metal carabiners can be worn severely by repeated lowerings in a small amount of time. Use a super light carabiner only when weight is absolutely critical. The larger diameter of these carabiners is gentler on your rope than that of lightweight, smaller diameter carabiners.