The abs and mid-section are truly important when one is in pursuit of a visibly impressive physique worthy of being called "chiseled". If one takes it a step further and zooms in on the different parts of the abs, the serratus really stands out as a most exclusive muscle. If you are muscular you can display good upper abs even when your body fat percentage is rather high - bodybuilders that are really lacking in overall aesthetics can still display a kind of six pack, be it bloated and less than satisfactory, but still, undeniably a six pack – but for the serratus to be really visible requires you to be in great shape. Defined and clearly visible serratus muscles makes for a truly statuesque and chiseled look. They are the difference between looking “only” rather healthy and being top notch.
Last week I was able to achieve a remarkable soreness in my serratus. I did it by employing the best serratus-exercise there is, namely traditional pushups. Yes, that's right; in my opinion the best exercise if you want to target the sides of your torso is not what you would normally call an abs exercise, but instead this the most classical of all body weight movements. In last week's example I performed (as part of a chest workout) 10x20 pushups with short rest intervals in between. This sums up to 200 pushups - which almost guarantees soreness in the serratus the day after (provided, of course, that you don't perform tons of pushups every week, in which case the serratus will quickly adjust and you will be able to go through those 200 reps without feeling it the day after).
If you want to make a point out of the push ups' "serratus-effect", you can finish each rep by going a bit higher than usual - thereby performing the so called "serratus-pushup". Push yourself as far up as possible and then make sure to freeze at the top for a few seconds while really feeling your serratus burn.
Furthermore, if you want to target the serratus without straining the pecs and the triceps (which 200 pushups tends to do...), you can skip the whole down-to-the-floor-aspect of the pushups and be content to just make that last bit of pushing, starting each rep on already straightened arms, pushing yourself those last few centimeters that will make the upper back (the shoulder blades) the highest point of your body.
Let's start chiseleing away at those serratus muscles...