As far as teaching private lessons goes, I am relatively new but I can definitely say that I am learning quickly. I began posting flyers all over town on the stop signs, bus stops, cross walks, metro stop, and announcement boards. I think you really have to be strategic about where you put your flyers. For example, if you put your flyer on a street lamp on a small alley near your house I can almost guarantee it will only get looked a hand full of times. Whereas if you tape your sign right next to the entrance of the metro it will get looked at hundreds of times and you are very likely to get some investigative calls.
The way you design your sign or flyer is also important. I made the word ENGLISH much bigger than any other word on the sign and put it in bold. This way even if the people pass by very quickly the important part of the sign catches their eye and for the most part they already know what is being advertised. A lot of the other flyers I have seen are all in small font and you have to stop to actually read any of the words. Another basic piece of advice for your design and posting of the flyer is to put you telephone number as many times as you can vertically along the bottom and then cut in between each number with scissors so the people can rip a tab off your flyer with your phone number. As a side note to this, I also recommend you tape right above the phone numbers horizontally when taping your flyer to a pole or wall, so that when someone rips off a phone number they don’t rip your sign in half. Believe me this happens all the time and then your hard work of putting flyers up is ripped apart…. literally.
You must also be persistent with your work at advertising to be successful. A good idea is to check your signs weekly and take mental notes. Are the phone number tabs being taken? Is it still there? If a lot of the phone number tabs have been taken put another one up right next to the old one. It is obviously in a good location and people seem to be interested. If the flyer is gone it may be that the street cleaners took it down, some rowdy kids ripped it down, or the torrential Basque rain got the best of it. Either way, put up a new sign.
Another option for self-marketing is the Internet. I think the people in Spain use it a lot less than the people in the US, but nonetheless it is used. Out of personal experience, I think at least half of the phone calls I have received about English classes have been via Internet postings. Use Google to find a website like Craigslist.com or MundoAnuncio.com and post your ad there for private English classes. Make sure to post it bi-weekly or so because it will get deleted.
You can also search Google for good ideas on help for getting started with teaching private English classes overseas. There are lesson plans, or marketing ideas like passing out business cards and things like that you can find.
If you are looking for a reputable TESOL/TEFL course, I highly recommend Ontesol’s 100-hour TESOL Certificate – Learn how to create professional lesson plans online!