Seams Need to Be Neatened
Long seams such as the side seams of a dress, sleeves seams and even the waist seams do not usually need to be trimmed but they will usually need to have the edges neatened to prevent fraying.  There are several ways to neaten these such as:

Using an overlocker ...

Why You Should Pre-Wash Fabric Before Sewing
Let's make sure your sewing project turns out just the way you want it to!
One of the most common questions in sewing is whether you should pre-wash fabric before sewing. While it can feel like an extra step, pre-washing fabric can save time, prevent di...