How/where should the No5 mess dress trousers fit? I cant help but feel mine are really high on my body and look very silly. I know the trousers are tailored differently to No1 or No2 Dress trousers.
Where should they sit? belly button/mid back?
Any Tailors out there?
Just under belly button give/take depending on your “profile”. The back is tailored to go a little higher but not too much. When you wear the waist coat, you shouldn’t be able to see white shirt poking out.
They sound perfect.
Bear in mind that trousers generally have been on a downward trajectory over the last 100 years. Mess dress goes round your actual waist - not your hips like most of your trousers probably do. As POP says it is essential that when you wear a waistcoat (not just in mess dress) no shirt should be visible - that looks awful.
As I get older I find the higher trouser position more and more tempting. Apparently there is a direct correlation between age and waistband height in men (proper scientific survey).
Here I am…
Yes, Plt_Off_Prune is quite correct.
Mess dress trousers are still cut as traditional, high-waisted, evening trousers. They should sit on the natural waist which is usually just below the belly button.
If you spot someone with low waisted trousers and white shirt showing between the trousers, waistcoat/cummerbund, and jacket be sure to nominate them for a mess fine 
It’s a hideous trend!
Indeed there should NEVER be shirt visible between waistcoat and trousers, ever. I blame the hipsters…
It’s one of my bugbears.
It’s called a WAISTcoat not a chestcoat. It’s meant to cover your waist!
Right up there with fastening the bottom button on a suit jacket and wearing a buttoned collar without a tie. Grrr.
I even saw one “lad” wearing a collar bar without a tie. What a wally!
Thanks for all the feedback!
What’s your line on double-breasted jackets?
I was taught single breasted - only do up one button (middle or top if only 2); double breasted - all buttons done up when standing, undo bottom buttons when sitting.
Generally I still think they look better with the bottom button unfastened, but there is a bit more leeway with them.
You could get away with fastening them all. Though I always like to think if it’s good enough for Cary Grant… 
Just don’t commit the unforgivable sin of only fastening the bottom button. Ugh!
These days though I think a double breasted suit is harder to pull off without looking dated. It works for some men but not for others.
