Begin by choosing a well ventilated area to work in. I strongly recommend that any spray painting job be done in the garage or workshop; not in the house.
Cover the area with old newspapers to prevent damage to the floor or table from over-spray. Move any valuable items well out of the reach of the spray.
Spray a thin even coat of spray paint on the object and allow to dry.
You can spray paint outside under optimum conditions. Choose a warm clear day with no wind. A sudden gust of wind can carry spray paint much further than you may anticipate.
Find a location that is away from buildings, flowerbeds, clothes lines or anything else your mother might consider valuable.
Spread an old tarp on the ground, otherwise you will end up painting the lawn, too, and that's sure not to go over well, either.
Spray the object with a thin even coat of paint and let dry. If you want a thicker coat of paint reapply once the first coat has dried.