In constructing the perfect sandwich one must consider first the ingredients. I suggest before ever laying mayo to bread that you reflect seriously on the cosmic ramifications of what you are about eat. To help you in your meditation here are a few guidlines that I've found helpfull over the years.
1) Never put Legos in your sandwich, very bad
2) Never make sandwiches whilst pooping
3) Try to think happy thoughts such as rolling naked in a field of sliced turkey
4) If at any time you become covered in angry biting insects like ants or spiders abort the opperation!
5) Don't drink the mustard!
6) If your sandwich behaves strangely i.e. levitates, talks, or try's to bite back, strike it down with a hammer or other deadly object until the sandwhich submits to you.
7) It helps to use positive reinforcement with your sandwich. Tell it things like "good sandwich," or "your a very beautiful sandwich"
8)Abstain from having sex with your sandwich, sandwiches are for eating!
9)Consider the feelings of others and always remember that people are generally just bad and they will conspire to take your sandwich from you. If this happens I suggest the use of a flame thrower to persuade them to leave your sandwich be.
10)Never let a homeless person or giant talking cockroach make sandwiches for you, they are unclean and should be shuned!
Follow these simple guidlines and you too can be a prince or princess of sandwichology. If you still feel unsure about the whole business, don't hesitate to consult me.