These days most of the times when you purchase a new phone the earplugs you get along with the phone are not of very good quality and they get wasted in about a month or two. And earphones are essential amongst the accessories for any phone. So here are my tips,
Purchase a earphone which has the best build quality like JBl or sony. These may cost you a few more bucks but they are worth it.
Check the user reviews on any earphone you are purchasing online because online products may fool you sometimes.
Try to purchase from a genuine website which sells genuine product and gives it invoice.