As a banker for 28 years, skirts were mandated. Here were my solutions (now retired, o jeans are the daily wear):
1. Buy skirts with pockets (dresses also). Pocket corners can be opened in a dress to thread the tubing from the insert location to the pump secured in the pocket.
2. Make pockets for skirts. There are two ways. I often sew together 2 3" X5" pieces of lining fabric and sew the top edge into the waistband stitching. Unless the dress/skirt is very form fitting (NOT IN MY WORLD!!!!) it will hang inconspicuously between the skirt and body. You can make the "sleeve" longer, so it hangs in the most inconspicuous location. OR
3. Use baby socks--fasten them inside a skirt waistband--I use a small binder clip--same as above.
4. Bra is great also.
Only problem have with these methods (I use them all the time...) is the inability to discreetly access the pump. It was embarrassing when the pump in the bra alarmed in a meeting...
In conclusion, I am a most definitely a pants with pockets girl. I will not buy pants that do not have pockets. It solves all the hide the pump, access the pump easily issues.