Help for an absolute beginner

[Shangas]

Waistcoats are highly variable.

You have everything from lapels, no lapels. Single, double breasted. Anything from four to eight buttons (the norm is somewhere between five and six). And two to four pockets (although I do have one waistcoat which has SIX pockets). They might or might not come with a cinch at the back to tighten the waistcoat to make it more form-fitting. Traditionally, waistcoats are silk-lined.

A good-fitting waistcoat should be form-fitting without being constrictive.

If it bunches up on you when you sit down, it's too small and tight. Or you have to lose weight. If the armholes are way below your armpits, then it's too big and loose.

Some modern waistcoats have pockets which are more for show than anything else. A functional waistcoat will have pockets which are at least two or three inches deep. Don't forget that waistcoat pockets are used to store your pocketwatch, so they need to be deep enough to stop the watch falling out (but not so deep that they swallow the chain as well).

 

[avedwards]

I'll tell the tailor I'm going for something like this or like this and tell him what you guys have pointed out. I found both of the links in this forum
Is there anything I should know about waistcoats? I wasn't going to get one, but I might change my mind.

As for the trousers, I hope it'll be alright if I just asked for a full-cut pair with cuffs, pleats and a high waist.

Both of those suits look like they'll be good inspiration for a tailor. Make sure the tailor looks carefully at the shape of the shoulders if you want the suit to look as authentic as possible.

The only consistent thing with vintage waistcoats is that they are usually several inches shorter than modern ones, though by how much will vary depending on your height. The reason for this is that modern trousers are worn lower so the waistcoat has to be longer to cover the waist.

You should be all right if you ask for trousers like that as long as they are properly fitted to you.