This is very simple and a great way to build comfort by making the target think you know all of her favorite things.
All you need:
6-8 small pieces of paper
Tell your target (or obstacle) that you can read her mind. That you'll be able to see what a few of her favorite things in the world are. Split the amount of paper between the two of you and pick up a pen each. Tell her to write down her favorite movie star without letting you see whats shes writing. As she does, you write the word carrot on your paper. Both of you put the paper into a separate cup. Ask her what she wrote down. If she asked why, tell her it's so you can know if you need to get a better read or not. She tells you. Both pick up another piece. Ask her to write her favorite band. As she does this YOU write down what her FAVORITE MOVIE STAR WAS. Put the paper into the cups. Ask her what she wrote. Then tell her to write down a vegetable. As she does, write down what her favorite band was. You should already have the word carrot written down on the first piece of paper. Finally, reveal your matches to each other and she will be blown away. Since 9 out of 10 people write down carrot as the vegetable, you should be cool. If not, 2 out of three ain't bad. You can add more favorites if you want (best friends name, color, movie etc), but I like to stay with either 3 or 4. Have fun.