Try taking a small classified advert in "The Singapore American" monthly newspaper which is mailed out free of charge to the American & Canadian community here. You can get on the mailing list if you phone the American Club and ask for the no. as they're based in the Am.Club premises. Again, the same for the "Bamboo Telegraph" which is the monthly magazine of the American Womens Assocation, also located in the American Club in Scotts Rd.
You could perhaps ring SAS, the United States Information Service (ask Directory Enquiries or the US Embassy for the phone no.) or the Canadian School too and see if they have newsletters you can advertise in. Or the "IS" magazine if you wish to tutor local students who hope to go to a US college.
Hope this helps!
