Wipe the excess oil off the drain hole on your oil pan and the drain plug with a clean shop rag. You can find red shop rags at your local auto parts store.
Inspect your drain plug for burrs and the threads for any damage. If you find damage, replace the drain plug with a new one.
Start your drain plug gently in the drain hole of the oil pan, being careful not to cross threads while starting the drain plug, because this will cause oil to leak from around the oil pan's drain hole.
Tighten the drain plug by hand until it is fairly tight, making sure not to cross any threads as you tighten.
Pick up a crescent wrench and set its adjustment to match the width of the nut on the drain plug. You may want to wipe the drain plug with the shop rags again to limit the amount of oil that gets on your crescent wrench.
Turn the drain plug with the crescent wrench until the drain plug is snug. Do not overtighten, as this can cause the threads to strip, which causes oil to leak out from around the drain plug.