Pick a "Style":
As mentioned before, anybody can make an Internet comic. The only thing that separates your piss-poor, chicken-scratch, black and white vague mess of lines from "Penny Arcade" is your comic's "style". Nobody on the Internet is a poor artist, they simply have a "different style". Here are just a few examples of the myriad of different "styles" you might see on the Internet:
Don't worry too much about the "style" of your comic, as it will undoubtedly mature and progress the longer you write your comic. For example, let's take a look at the noticeable metamorphosis Illiad's "User Friendly" has gone through in the roughly 19 years it's been up:
"User Friendly" - Old
"User Friendly" - Recent
If somebody like Illiad, who owns over 238 User Friendly-related corporations, licensing firms, and marketing companies can get away with such a major change in his artwork, just think of what you can slide by with! It's a rumor that Illiad has secretly been changing the genders of his main characters every month, but thanks to his artistic "style", nobody can tell!
Ask any cowboy and they'll tell you: The deadliest snake in the wild west is Lava-Filled Hole Shaped Exactly Like A Cowboy Silhouette
Garfield is a poison of bigotry on our culture and I have never been more offended on behalf of people than I am right now.
Ben Garrison's Cartoons are finally explained!
Something Awful Guides can help you, the Internet reader, make the most out of your life and just might possibly end up getting you incapacitated or killed!