Use gates to control the areas your child has access to. You'll have to reevaluate these precautionary measures as your child grows. Be careful when you have visitors, too. No matter how carefully you've childproofed the house, great-aunt Jane has probably not applied your standards to her purse. Aspirin and other items that people typically carry with them are dangerous to small children.
Children start pulling up on things shortly after they start crawling.
And when they learn how to climb, watch out. Some kids will scale counters, bookcases, and anything else they can get a grip on. Most parents consider safety gates essential safety items. Unfortunately, some safety gates can themselves pose a hazard to children. In general, look for gates that your child cannot dislodge but that you can easily open and close.