Catch a lightning bug. As you cup it in your hands, whisper your wish to it. Set it free. If it flies out of sight instead of landing nearby, it has gone to make your wish come true.
Put a lightning bug on the back of your ring finger, as though it were the jewel of a ring. Wish for some kind of jewel. If the bug glows, you will get the jewel some day. If it flies away without glowing first, you won't get such a jewel.