How to unclog your drain using a plunger
A cup plunger (a plunger with a wooden handle attached to a rubber cup) will most likely be the best option for the flat-surface drains found in most showers. To unblock the drain, place the rubber cup over the drain and push down on the handle. This action will force air through the drain.
Continue plunging with quick thrusts, directing the pressure down the drain. Take care not to lift the plunger too high (as this will break the seal).
Repeat these steps for 20 seconds. When you finally remove the plunger, the drain should be unclogged.
How to unclog a shower using a drain snake
The next tried and true method requires a little more elbow grease. For a stubborn blockage, remove the drain cover and grab a wire coat hanger.
Straighten out the coat hanger, leaving the hook on the end. Feed the wire down the drain and hook out hair and other debris.
How to prevent your shower drain from clogging
Naturally, the best solution to a blocked shower drain is prevention. Once a month, when cleaning the shower pour ½ cup of baking soda down the drain with hot water once a month will do the trick.