A lot of people experiment with adding more spices to the ketchup or relish or get a special kind of mustard, but that will greatly limit your customers to those that prefer your ‘special taste’. Your objective should be to perfect the simple taste. Yes, we come back to the simplicity clause again.
One trick that I learned down the road is that rather than spending too much on big brands or expensive alternatives for mustard or ketchup, I could greatly increase the quality of the taste by purchasing better quality buns and hotdogs. As it turns out, mustard is just mustard, and hardly many people ask for ketchup anyway. As for relish, unless you are serving Chicago style, a decent quality relish would do the trick. Again, experiment with a few sauces before you find a quality product at a decent price.
As for hotdogs, the most expensive aren’t always the best, and the cheapest wouldn’t necessarily save you the most money. Low priced hotdogs have high contents of fat that can easily burn and turn a dark brown and while they are still servable, the chances are they wouldn’t really go well with your customers.
Next come the buns. The good thing about buns and hotdogs is that you don’t necessarily need a branded product, as the customer would never really see the brand name. However, a customer will easily identify poor quality. Look for buns that will hold up better in the steamers; again experiment with a few products until you find the right one.