If you need immediate service from a plumbing company, you should find one that happily offers it to their customers. Some even specialize in providing fast repairs and replacements. If you think you need this kind of immediate help, you should learn what to look for in a local business.
If your service provider has adequate knowledge and training on the topic, this might be a good time to find out more about energy alternatives. He may be able to install low-flush toilets and lower-output shower heads. This is also a good time to talk about solar thermal water heating, though perhaps before the roofer is finished up top.
Your third option is a regular garden hose. Bring the hose in through a door or window (have it turned off, of course), put it down the pipe as far as it will go, add towels and rags around the drain to keep water from backing up, and then get a partner to turn it on and off in short spurts. The pressure from the water might work slow drain to loosen the clog.
For instance if you are looking for a Trustworthy plumber, you can post a tweet in Twitter and ask for referrals. Be careful of spammers who may connect with your keywords. Trust the comments that come from within your network.
Now to prevent clogs from happening, you would need a drain cover in order to stop the clogging. However bear in mind that sometimes the best idea is to simply call your Local plumber and have them come out to take care of the clog. It is simply the more financially responsible as well as reasonable. Plumbers have equipment that the standard homeowner doesn't in order to clear the drains quickly and get them flowing again. Just remember that you have to be specific as your plumber is not a mind reader and cannot diagnose on vague information.
Before choosing any plumbers in your area be sure you pick a contractor that has experience with similar projects as yours. Plumbing in your area isn't the same as say New York or Chicago, unless of course you are from one of these cities. Ask for a reference or two for plumbing jobs that they have completed in the past.
Once the work has been completed, ask for a breakdown of the bill before it's paid. That way, you know what you're paying for and it stops the plumbers asking for more money down the line.