Stringing an acoustic guitar...neatly wound vs. sloppy?

While it is not a big deal there is some functional advantages for having a neatly wound string. One advantage is that the string will pull down across the nut at a better angle and help eliminate tuning problems. Evenly wound strings will also not slip or stretch as much. This is actually very easy to correct by using an inexpensive string winder available at any music store. Loosen the string so that the windings are "loose" around the machine head post. Hold the string with the right hand so that there is tension on it and use a string winder to slowly tighten the string. Be sure that the windings are even and descending down the post. Thicker strings only need three or four winds, thinner strings need six to eight winds. This takes a bit of practice so don't worry if it is not perfect. You will eventually be able to do it perfectly!

Agreed.....it doesn't have to look perfect. Eventually, even if wound sloppy, the strings will settle in.

The key is to keep the string tight with your right hand with some finger gymnastics and hold it olw and let it wind upwards. this comes with experience.

it doesn't really matter much, as long as you got the string coiled around the post at least once

It should be just fine. As time goes on and you do it over and over again you'll get better (that is, neater) at it.

Looks good. Can you string my guitar for me?