Generally, non sequitur fallacies occur accidentally or, in some cases, in complex arguments where the arguer is hoping the leap in logical order will pass unnoticed. Basically, a non sequitur is when an argument logically moves from A to B but then skips C and jumps to D. When this occurs, there is a hole in the argument and the argument's conclusion can seem to come out of nowhere.
Example: Mr. Spagnolo really wanted some bacon. He went to the store and bought some applewood smoked bacon and a new frying pan. He cooked the bacon in his brand-spanking-new frying pan. Therefore, it is unwise to have bacon be the first item cooked in a new frying pan.
Example: Sometimes Non Sequitur advertisements can have humorous results... what the heck?