First, consider the type of terrain you'll be snowboarding on. If you're mostly riding groomed slopes, then you'll want pants that are specifically designed for snowboarding. However, if you're more of a backcountry rider, then you can opt for pants that are versatile and can handle a variety of conditions.
Next, consider your body type. Pants that are too tight or too large can be uncomfortable and make it difficult to move around. Look for pants that fit snugly but comfortably.
Finally, consider the features you need in a pair of snowboarding pants. Some of the most important features to look for include waterproofing, breathability, and insulation.