If you are writing a comedy, the first thing you need to do is decide if it’s going to be the kind of comedy that has fart jokes, or the kind that doesn’t. There's not a thing wrong with either of those comedic styles, but you just want to be sure not to intermingle them since they don’t get along at all. You are either Farrelly brothers or Woody Allen, but not both. Slip a fart joke into “Bullets Over Broadway” and you would lose the audience instantly. Try to shoehorn an existential diatribe into “Dumb and Dumberer” and the audience would revolt by directing actual fart noises at the screen. Pick one comedic style and stick with it.
Once you have decided what kind of comedy you want to write, then you need to start making the audience laugh right away and keep the laughs coming at least every one or two minutes throughout the entire script. That’s a lot of laughs and at least one out of every four of those needs to be a big belly laugh. The only way to generate that many laughs is through a combination of funny dialogue, visuals, character traits and plot line. You need to take full advantage of all of those comedic options in order to fill your comedy with enough laughs to get it past the first reader. If you can do that, Hollywood will beat a path to your door because good comedies are far too rare in this industry.