I have a bunch from Ikea and two cute ones from Gap Outlet. One of my Gap ones is a swimsuit bag so it has a plastic lining, I put all my suits in it but good for a suit that isn't quite dry when you leave. This was a lifesaver on our honeymoon road trip as my husband and I each had one, so if the suit wasn't dry in the morning we put it in the bag so it could hang tight until the next hotel room. The other Gap one has a clean and dirty side. I use one side for panties and the other for socks so they are always together and sorted.
I have 3-4 of the large Ikea cubes. I find them in the "as is" section for $1-$1.50. I take them home and wipe down with a Clorox wipe. I prefer large sizes so I can do one tank cube, one short/pant cube, one pj cube etc. I did buy one full set once and use the smaller bags for other random items. My shoes go in dust bags too. The cubes just let me pack more efficiently and I don't tend to overpack as I only pack what would fit in that categories cubes. Now that being said the Ikea bags have had some fraying on the inside from the fabric seams but for the 2-3 trips I take a year I was not about to buy the premium cubes. I also have been know to use those mesh delicate bags you get in the laundry section if I run out of cubes. I have them for laundry anyway.
One thing I find is you pack with the suitcase down on the ground and then it stands up, so the clothes will always shift. They get there in better condition and things can't slide around in cubes. I pretty much don't have anything loose in my suitcase anymore, even everything in my carry on goes in a bag or pouch. I also don't need to unpack if I don't want to, this is helpful on road trips. I just shift the cubes around and pull out what I need.