Okay, I’m the first to admit that I’m not fond of following the rules; straight lines are for the birds. However, when you have signed yourself up to follow the lines, it seems counterproductive to deliberately cross them.
Parallel structure is one of those things that is de rigueur in formal writing (though you’re welcome to toss it out the window when it comes to poetry and informal dialogue). It’s difficult to explain in detail: do you understand what I mean when I say just make it all the same? When you have several words, phrases or clauses strung together with commas and/or conjunctions, make sure all the verbs and all the articles follow the same pattern.
Here’s The OWL’s page on parallel structure, and another nifty little page from Bellevue College with some exercises on the bottom.
If you already have parallel structure under your belt, at least look at the Really Great Example they have on the Bellevue page: a mark, a yen, a buck or a pound. Try saying that 10 times and see if it gets stuck in your head. 