If you've got a small group of people, then try scheduling a casual coffee break at your local Starbucks or a hometown café. Make them feel relaxed as you let them know about SFI and the benefits it entails.
If you have a large enough group, then I'd suggest organizing a luncheon or a meeting. Provide refreshments. Snatch up some stationery so that your students can take notes. After that, you're all set.
