The eternal question of 'what to do with all these scraps?' had many answers in the 18th century when little went to waste.
As a modern businesswoman and seamstress I tend to stash tiny bits of silk, trim & brocade because I can't bare to throw it away when I paid so much per year... after all, I just know I'll need that 1/8 yd or 2" strip of whatever eventually. When I accumulate so much scrap that it becomes clutter, it's time to get sewing!
A very good thing to do with small pieces of fabric (aside from patchwork quilts) is to make accessories.
In the 18th and early 19th centuries men and women carried pocketbooks or silk purses. Important documents, money, love letters, scissors, sewing kits, etc. were kept in these tiny works of art.
Most were heavily embroidered and highly prized. They were given as gifts by very close friends, or purchased for important occasions such as housewarming or wedding gifts. Not everyone had a pocketbook.
Most commonly, pocketbooks had two main pockets with a 3rd or 4th sewn on top and a flap covering the added pocket. There could also be another pocket sewn on top of that to hold scissors, penknives or calling cards.
They could be made from silk, brocade or linen and were trimmed with gimp, silk ribbon or finished with cut edges and embroidery.
Men kept their pocketbooks in the breast pocket of their inner-most waistcoat. Women kept them in their pockets. These accessories were similar in function to a modern safety deposit box.
They are approximately 4" x 7" when closed and 8" x 7" when open. They can be larger or smaller, depending on the intended use or the available fabric.
If you decide to make or buy one, make sure it will fit in your coat / pocket.
A good place to see (or buy) historic examples is Vintagetextile.com. She has 3 lovely high-end examples at prices that are similar to other vintage sites.
This is a basic pattern without instructions (because there are too many variations).
This is relatively easy to make.
It's all approximates, you will have to look up historic examples and decide on the individual details of your pocketbook.
Bind all raw edges and be careful that any hand sewing doesn't come through on the inside of the pocket.
Remember to stitch the "bottom" edges closed or you will lose things in the far corners of the pocketbook. This won't be a problem if you bind all the way around, but if you only bind the sides you will have to do a narrow stitching line on each end.