(Click to enlarge)
You wouldn't know it from anything I've posted here, but I do actually have a dress form, neglected thing that she is. We met on Craigslist in 2005, when she was going under the name "Size Small Dritz My Double." I dubbed her "Matilda" for my favorite Roald Dahl character, and carried her home on the subway in a garbage bag, looking rather like a headless corpse.
A few months ago I even spent an evening "maternitizing" her to match my measurements at the time (PatternReview "review" here, for those of you who are members):

But I still continue to do all my pinning and adjustments and tweaking on myself in the mirror. I think we have trust issues. I've grown quite a bit in the belly and elsewhere since February, and she never REALLY matched my narrow sloping forward-rounded shoulders, or simulated my swayback... And don't tell her I said this, but her bust is a bit on the lumpy side.
Matilda isn't the first dress form in my life, either. Once upon a time (2001), I made a duct tape model. She turned out lumpy, lopsided and overstuffed, but before I could tweak her fit, I suddenly lost 15 pounds due to pneumonia.
Duct Tape me was relegated to my mom's sewing room, where she servers as a proud model for all the baby carriers mom has been sewing for her first grandbaby.
As for Matilda, she just sits quietly in the corner of my living room, modeling my muslins and hanging out my hems, poor girl. Someday I'll find a more accurate way of padding her to match my shape, and maybe even break out that draping instruction book...
Do you have a dress form? How well do you get along and how often do you really hang out? And does he/she match your measurements enough for your liking?