Decide who your target user is. Perhaps you want to make inroads into the Vietnamese community with an upscale smart phone. Then your target audience might be young to middle-aged Vietnamese-speaking Americans with incomes over $30,000 a year.
Create a plan to recruit people in your target audience for your focus group. For the smart phone example, you might offer an incentive of $50 off the phone and advertise that on the website of the wireless service.
Prepare for the meeting. Devise the focus-group questions. Keep them open-ended and pertinent to the topic, but also reflective of relevant cultural issues. Because the point of assembling a focus group is to facilitate a discussion you can learn from, you might want to consider recording the session. Also, select a group facilitator and location for the gathering. Have a native speaker conduct the focus group.
During the focus-group discussion, permit the facilitator to be flexible enough to allow spontaneous digressions from your prepared questions. Unless you are a member of the target culture, you probably don't know everything that the group might find interesting or noteworthy about the topic. The focus group might bring up points you hadn't even thought of delving into.
Analyze the results. What can you glean about this culture as it relates to your topic? What was surprising or different from other research findings? More important, what does it mean for your field?
Revise your document, product or theory to accommodate what you have found. Consider publishing the results so other researchers or academics in your field can learn from your focus group.