Plug Stoppers are cheap and easy to find. They are a great option when you have a baby that is just starting to crawl around. However, older children may realize that they can pull the stopper out of the plug and stick objects inside the holes. For this reason, you may prefer having an electrician install baby proof outlets.
Try getting cabinet stoppers that require an extra step before opening. If they are the type that let the door open a crack, be careful because a baby could still slam there fingers in the door.
A simple plastic baby gate is effective to close off certain rooms. If you have a dog or cat with food and a littler box in another room, for instance, you should block the entry way.
A pedal is a good start to child proof the trash can. However, they could still push down the petal and get inside. An additional stopper on the top of the can is a great extra precaution.