On the board, have two options:

 I think this is probably true about the teacher.

 I think this is probably false about the teacher.

Prepare some sentences about yourself. Alternatively, you could tell short stories about yourself. Include some that are false.

My hobby is bungee jumping.

I play guitar.

I have a twin brother.

When I was a child, I was on a TV show on the Disney Channel.

Let Students Discuss Before Answering

Instead of having students answer immediately, you can give them a couple of minutes for discussion in English before you ask to see their answers. They can discuss in pairs or in small groups. This allows them some real communication in the target language. Also, the "pressure" of showing an answer at the end of the short discussion provides some real motivation.

Dicussion, with Questions

If you're giving students a few minutes to discuss your story before answering, why not allow each pair/group to ask you one question as well?

Answer, Discuss, Answer Again

Another technique that is useful here is sometimes called, "Answer, Discuss, Answer Again." 

1. Students give their own answers immediatly.
2. Then, while holding their paddles, they move to sit with one or two students who gave a different answer.
3. These pairs or small groups discuss the reasons for their answers. How do they know? Can they convince the other students that their answer is correct? Students are more often more motivated to discuss or defend a position if they have already given an answer.
4. After a few minutes, ask for students to answer again.

Students Turn: How Well Do You Know Me?

This works just like "Students Speculate" above, except that the students are in small groups of about six. Students take turns being the center of their group's attention. Each student reads out a few sentences about themselves, and the others in the group respond with their Captur tools (A for true, B for false).