While there are some plumbing repairs that you will definitely need to call a professional to help with, there are several minor problems that you can take care of yourself in between service calls. Unclogging stubborn drains is one of the easiest, but it depends on the severity of the issue. If you have multiple drains that are backing up, that indicates a problem with your main sewer line and requires a professional to look at it immediately. If it's just one drain though, you should try one of the below remedies that involves resources that you can get over the counter at just about any store.
It doesn't get much more basic than a bent metal hanger, but the old standby is still one of the most effective tools at unclogging stubborn drains. Simply grab a metal hanger and bend the end into a hook, and then lower it as far as you can into the pipe, being careful not to scrape the edges, since it could potentially damage the drain. If you want even more control, put on a pair of rubber gloves and reach in the pipe with your hands. If the clog is superficial enough, you should be able to dislodge using your fingers.
One of the other most common tools to unclog a pipe is the plunger. Lower it into your drain and create a seal around the opening, and then pump up and down vigorously to use the air pressure to dislodge the clog. While these are commonly used in toilets, you can even potentially use them on the drains in your kitchen and bathroom sink. The only thing you need to do is make sure that you have a tight seal around the drain opening.
Hot Water and Soap
If that doesn't work, grab a bucket of hot water and pour it in gentle drips down the drain. Don't splash it all at once or else it will overflow your toilet and could possibly even cause water burns. If you want a little extra lubrication, put a squirt of dishwashing soap inside of it; that should help the clog slide out easier. Make sure that you don't use boiling water, as that could damage old and plastic pipes.
Salt and Baking Soda
Take half a cup of salt and a half cup of baking soda and put them in a single container, then pour it down the drain. You'll want to let it sit for around 30 minutes to allow the concoction enough time to eat away at the clog, but if it's especially stubborn, let it sit overnight instead. Once you feel like enough time has passed, take a pot of hot water and pour it down the drain to remove all the gunk.
If these techniques don't work, call a plumbing company, like Laroc Refrigeration-Metal Division.