3. Thy wiener shall be made of meat
(... or not, for you vegetarians.) For carnivores, beef, pork, veal, or some combination thereof are preferred. As with all meats, the source is important. Your local butcher is usually going to be your best bet and there are certainly acceptable brands in your supermarket. In Chicago, just use Vienna Beef. They're the best.
4. If thou is in Chicago, thy relish must be sweet and nuclear green
Thou shall not ask why. It just goes like that sometimes. Also, that sweet/salty thing is recommended. Adding shredded cheese or a crunchy topping (onions, sauerkraut, jalapeños, etc.) is also highly recommended. But in moderation: don’t overpower the hot dog. Sometimes the simplest combination of condiments is the best.