Is it possible to make the waist on a pair of trousers larger by a inch or two? Found these grail Yohji trousers but they're too small in the waist
>is it possible to make by far the easiest and most common alteration in all of tailoring
Yes. Yes it is. Take them to your tailor. As long as there's excess fabric in the back it'll be a piece of cake, if no he'll have to inset a wedge of material and you'll end up having a small cut of actually good black tweed in the back.
Tailor here. It depends on how they're made. Check out the back of the waistband. Is there a seam in the center back? Is there extra seam allowance on the back crotch seam? If the answer to both these questions is yes, then no problem. If not, difficulty ensues. >>10930080's idea of adding a gusset will work, but look like complete garbage and ruin your fancy pants. Don't do that to Yohji. Sell them again and wait for your size to come down the resale stream.