It is very important that you not repeatedly flush the toilet. Flush only once to determine that the toilet is clogged. Flushing multiple times can cause a toilet to overflow.
Prepare Yourself and the Area
Before beginning to unclog the toilet, lay newspaper or paper towel around the toilet in case the toilet happens to overflow. This will also help in cleaning splashes and other such things.
Place your plunger at the base of the toilet, covering the drain completely and creating a seal. The power that makes plunging effective is pushing water, not air. If there is not enough water in the bowl, add some until the rubber of the plunger is submerged.
With the plunger in position, pull slightly towards you and then push down. This creates suction and then pressure. Repeat this a few times. If water drains from the bowl but the toilet remains clogged, add water again and repeat. It may take a few tries to get a toilet unclogged.
If you toilet has been clogged by a toy or your attempt at plunging was ineffective, you may need to use a plumbing snake. Go to your local hardware store and seek one specifically developed for a toilet, known as a closet auger.
Place the end of the auger down the drain of the toilet and push down feeding the pipe into the hole until you feel an obstruction. Once you reach this point, twist and push the pipe further until the obstruction loosens and the toilet drains properly.