NOTE
I haven't updated or used this activity in awhile. If you are going to use it you should take a good look first for dated cultural references and stuff that doesn't suit the new teacher strategies. If nothing else I hope these older materials will give you some ideas for your own materials.
Practice the dialogue. There are six requests. Select three and circle X and select three and circle 0.
Make a pair and take turns playing both roles in the dialogue. When you make the request and if you pick one your partner has circled the 0 your partner says 'Sure' then after the dialogue ask for a sign. If you pick one with the X then your partner responds 'Sorry I can't' and you don't get a sign.
Regardless switch roles, do the dialogue a second time and then say goodbye and find another partner.
Continue until the teacher calls time up and see how many signs everyone has collected.