One of my biggest regrets was not learning to sew. I remember be in Grade 8 and being told girls had to take home economics which translated to cooking, then sewing. Boys got wood working and machine shop. So I got out my soap box and began preaching about the misogynistic society in which we lived trying to keep this woman in her place. My righteous indignation took over my common sense and I promptly failed the sewing portion of the class, but  felt justified  because I was a strong independent woman teaching society a lesson. Truth is no one cared, my grade point average dropped and my mom has the ugliest, misshaped pot holders ever made. The point I am trying to make is that I wished I had the skills to alter clothes to fit my body properly. Too often I see plus sized or for that matter, any woman, wearing clothes that are too big, too tight and poorly fitting their body. Plus sized designers have a unique challenge when it comes to making their clothes work for a variety of women. This is because we curvy women have a variety of shapes and sizes and despite designers best efforts, one 2x blouse will not properly fit all 2x women.  Because I cannot sew (bless my sweet husband for sewing on my buttons), I have found a seamstress who fits my clothes to my body shape. If you don't want the expense of altering your clothes, I suggest a good thing to learn is your proper measurements.    

When shopping for clothes on line, you can use your measurements to help you choose your correct size. Most clothing stores have sizing charts that tell you what measurements each of the sizes are made to. If you need to know more specific measurement, contact the staff's site for more information. Quick tip - Remember that international sizing is different. If the site does not have a conversion chart, here is one you can use, http://www.onlineconversion.com/clothing_womens.htm.
When shopping in store, make sure you try on the clothes. I know some women who are embarrassed and just want to get in, get out and not have to talk to any clerks. But when you take the time to try on the clothes, you can see how the fabric falls and what the cut feels like. Walk around a bit in the garment to see how it moves with your body. That way you can avoid clothing that clings were you don't want it to, becomes shapeless and does nothing to flatter your curves.