A bit counter to the prevailing zeitgeist, but I would caution
not to make an infallible guru out of any one particular bootfitter if you have tricky feet.* Don't be afraid to disagree based on your own experience. There are many knowledgable people in boot-related discussion threads and plenty of reviews to read and compare. The forum posters will disagree forcefully, the magazines will advertise product, and shop staff can only show you what they have in stock. In the end, nobody is more committed to your boots fitting properly than you are.
Since only last February, at reputable and recommended bootfitters, I have:
1. been sold a boot with a 104mm last for my insanely-narrow feet. (Fitter #1)
2. been sold a pair of rigid insoles that were always painful (Fitter #4)
3. been told that I needed heel lifts. (Fitter #1)
4. been told that under no circumstances should I use heel lifts. (Fitter #2)
5. been sold a new pair of narrower boots [
97mm, size 27.5] only to find that they, also, were too big. (Fitter #3)
6. decided to switch to the same boot in a
26.5 and punch out the toe. (#3)
7. been told the 110 flex was not in stock, but that the 130 flex boot can be "softened" so as to reduce the flex by removing the bolts at the back of the cuff. (fitter #3)
This did not work. I was told there was "nothing else" that could be done. Oh, and the boots could not be returned because they'd been punched. (Fitter #5)
8. had a second bootfitter adjust the flex further by cutting the cuff under the front leg buckle and taking out both nuts remaining inside the boot spine (because apparently something
could be done) (Fitter #6)
9. instructed in three distinct methods of buckling ski boots (Fitters #1, #2, and #5)
10. listened to each boot-fitter disparaged the choices made by his colleagues in other shops.
My point is that there is a benefit to being a well-informed consumer, and that there is a wealth of information to be had on boot fitting forums and articles. You still want to have boots fitted by a professional, but that doesn't mean subordinating your own judgement or that it's wrong to ask questions on a forum.
*I always have issues with footwear that needs to have a very precise fit (hiking boots, ski boots, running shoes, etc.) because my feet are crazy long, but also narrow and low volume. Women's footwear rarely comes in my size, so I have to make it work with men's.