I've used spibelts and now I'm using those and another one from pumpcases on amazon. This one has a vertical pocket that opens with a Velcro closure which I like. It's easier to get at my pump. They do tend to move around more than my Spi belts The pumpcases one comes in different sizes so you can use it on your legs or arms too. I use mine in my waste and I clip my Dexcom on it too. I'm going to get a soft flannel one soon for more comfort when sleeping. I have to wear mine under sleeping clothes so my kitten doesn't chew the tubing.
I've given up on dresses because I don't like the band around my waist with a dress. I leave my pump out in the open mostly so I can access it- sometimes it's under my shirt or jacket a bit. I dont want to have to start going into my bra or lifting up my dress to bolus etc. pockets were not reliable.