Have you ever thought that deep down you really were not a nice person? If no, this guide probably is not for you. If yes, congratulations, you're well on your way to becoming an Asshole! If you follow these easy steps, you will be able to ensure that people think of you as an asshole, and not as a mere jerk, putz, loser or boor.
Step One: Have impossibly refined sensibilities
This is the most essential step to becoming an asshole, and probably the most difficult. It requires an amount of study because you will need to know your field. Faking is not an option; a fake will be held up as an object of scorn and as a pretentious moron, which is clearly not your objective. I'd suggest specializing in a particular area, like food or music. While General Assholery is spectacularly impressive, it requires nearly a lifetime of study to properly attain. Knowing your field means knowing it utterly; if you intend on being a Food Asshole, you'll not only need to be able to instantly tell the difference between a good Chateau Lafaurie-Peyraguey and an indifferent Puligny-Montrachet, you'll need to be able to expound to your host or hostess on why the former would have been a much better choice to serve with dessert.

Step Two: Use Really Big Words
This is a much simpler step in your ascendance to Divine Asshole. All you'll need for this is a thesaurus and a dictionary. Take some common place words and replace them with obscure ones, instead of "beauty" say "pulchritude", instead of "childish" say puerile. Make certain that you are properly using your new obscure words; loudly correct anyone who uses them improperly.

Step Three: Choose something to hate
It doesn't matter what, as long as it is something almost universally loved. Don't hate the French if you're English. Don't hate the Backstreet Boys or N'Sync, or you may be mistaken for a wit instead of an asshole. Whatever you do decide to hate, make sure you know enough about it to hate it properly, I'd suggest hating something in your field of expertise. If you're a Food Asshole, hate Italian Cuisine, if you're a Music Asshole, try hating Mozart or The Beatles. Make sure that whatever you do hate, is common enough to come up in casual conversation; if you're an Art Asshole, don't hate Gustave Caillebotte, as it's hard to bring conversation repeatedly around to lesser-known impressionists.

Step Four: Always Manage to Turn Conversation around to you
No matter what the topic of conversation is about, make sure you play a starring role in it. If someone is complaining about their hateful and psychotic ex-boyfriend, tell them all about your evil ex, who was way more evil and psychotic then theirs. If you don't have an ex, make one up. If someone manages to mention something remotely related to your field of expertise, monopolize the conversation. If possible, turn the conversation back to the thing you chose to hate in Step Three and complain loudly about it.

Step Five: You Are Always Right, Be Secure in this
This is the culmination of your training as an asshole. Once you have mastered the first four steps, you are ready for this. When someone decides to argue with you about the merits of the thing you hate in step 3, intellectually bludgeon them using the words you learned in step two. This should not be especially difficult if the hated item is one in your area of expertise from step one. Resort to ad hominem attacks deriding your opponent's intelligence. Don't be overly concerned about being clever, witty or eloquent; you are an asshole afterall, not a bitch. If you manage to win the argument either by logic and reason or by your opponent leaving in disgust; be an ungracious winner and taunt your fallen foe.

If you carefully adhere to the above steps, you will be a Supreme Asshole in no time. While you may not have many friends, you can be secure in the knowledge that being an asshole is always better than being a jerk or a loser; they not only lack friends, they lack style.