The banner for communion should have symbols for the wine and bread shared at the Last Supper. These may be a loaf and a chalice, or may be grapes and wheat. In addition the banner may have such symbols as the cross or dove representing sacrifice and the divine Spirit. A First Communion banner will have the participants name also.
You can use symbols of your family, a chalice, dove, olive branch, cross, sun, hands in prayer. The banner should include things that have meaning for the communicant.