Clogged Toilets
If your toilet isn't flushing properly, you can use a plunger to get the clog out of the system. Push the plunger into place, create a suction seal over the drain hole, and pump the handle up and down.
Be careful not to flush the toilet unless you're successful in unclogging the pipe, as you could flood the bathroom otherwise.
Sink & Shower Drains
If water isn't draining properly in your sink or shower, you may need to clean the drain. You can get plastic cleaning tools and chemical cleaners at most hardware stores.
Be careful not to use any products that aren't designed for plumbing use, as these could damage the pipes.