One factor that you will want to take into consideration when shopping for earbud headphones is the length of the cord. You want something that is long enough to give you freedom to move without giving you so much cord that there is no comfortable way to store the excess cord.
You will also want to inspect the control buttons or knobs to see that they are comfortable for you to use. You also want these controls to be easily accessible, so you can easily adjust your background noise reduction quickly and easily.
Look and style is important you will also want to pay close attention to comfort and fit. Many earbud headphones offer custom fit options. Another common feature on earbuds is the ability to be wireless. Wireless earbuds are a great way to have freedom of movement when you are going to be close to your music device but don't want it attached to you, such as when you are working out or gardening.
The main difference in earbud headphones besides fit and style is the sound quality that is produced. While the standard relatively inexpensive headphones will be fine for most situations, you may find that your listening needs mandate a higher quality of sound production.
No matter what your listening need or your taste preference there are many retail stores where you can find a wide variety of earbud headphones. Most electronic stores carry an assortment of quality and style of earbud headphones. Another convenient location to find ear buds is at your local pharmacy such as CVS or Walgreens.