Smaller locs are more pliable. If you have thinner hair smaller locs would most likely be the best route. Smaller locs can be easier to style depending on stylist preference. Smaller parts means that you can section the hair in smaller sections to achieve a greater variety of style. It is also easier to interlock smaller locks. Smaller locs are easier to set on rollers as well. Larger locs = fuller locs. They take less time to start as well as retighten. Styles can vary with larger locs as well and they longer they get the fuller the style looks. Most lock jewelry is created for medium-large locs. Loc petals look fuller with larger locs.
It is important to determine the size of the lock you want because this is a permanent style. If you want your locks smaller, and they have already locked – there is a way to do this. If you want your locks larger and they are locked there is a way to accomplish this as well. Both of these techniques take a longer time period so it’s best to decide what size you want early on.