Always make the smallest hole in the leather that will still admit the piece you want to insert. You should always stretch the leather a little to admit the piece, rather than having it slop around in a hole that is too big.
Rivets and studs should be peened up rather than just folded over on the inside of the belt. Put the rivet (or stud) through the hole and clip off the excess material on the back to about 1/16 or 3/32 inch (2 to 2.5 mm.). A nail clipper is a good easy-to-come-by tool to do this with. Use a small, light, crosspeen hammer, like a jewelers crosspeen or a tack hammer, to gently spread the end of the rivet/stud. Use many light blows, rather than only a few heavy ones.
Support the piece during riveting on a heavy stiff piece of metal (an anvil is ideal, but look round and see what you have). Put a piece of thin cardboard, like the cardboard on a pad of paper, between the metal support and the pewter while hammering, so the pewter is not crushed. Do not use leather or corrugated cardboard for this; they are too soft and the pewter will deform badly.
Buckles and Chapes with Sockets into which the leather fits
The sockets of these fittings all taper in on the sides trim the edges of your strap ends to fit the taper.(It's a good idea to make a pattern out of a little piece of cardboard and fit that to thesocket first.) After you have prepared the strap, slip it into the fitting. Holding both strap and fitting firmly to prevent their spinning, drill straight through all three layers simultaneously (pewter, leather, pewter) in the places where you want the rivets. Two rivets are enough (one rivet for small chapes). Use a 3/32" (2.4 mm.) drill bit. Press the rivet through the hole, clip it close to the back of the fitting (about 1/16 inch or 2 mm.), and peen it up. No washer is required; the back of the fitting serves as a washer.
Buckles and Chapes with folded attachments; purse hangers
Make sure the front and back parts of these fittings are aligned, then slip them over the leather and drill all the parts together, as for socketed fittings. For the purse hangers, make sure the purse hanger is tightly caught by the attachment straps, pressed up close to the strap, so it doesnt slip out.
Buckles the strap loops through
Fold over an inch or inch and a half (2.5 to 4 cm.) of the end of the belt. Punch or cut a slot for the buckle tongue to move in starting on that fold. Loop the belt around the buckle with the tongue coming through the slot. Punch or drill small holes (use awl, smallest hole on leather punch or 3/32 or 2.4 mm. drill) through both parts of the belt for the rivets that will hold the loop. Insert and peen up rivets against washers provided.
Make 3/16 (4.5 mm.) holes at the places where you want the eyelets. (We usually put one eyelet at the length you want to wear the belt and two more to either side, at one inch (2.5 cm.) intervals, to allow for different thicknesses of clothes, etc.) Put the eyelet through the hole. It is helpful to shorten the eyelet so only about 3/32 (2.5 mm.) stands out of the leather on the back, to reduce the amount of metal that has to be moved. A useful tool to do this with is a small curved nail or toenail scissors; it will not damage the scissors to cut smoothly straight around. Using a tapered punch, like a center punch, nailset, or commercial eyelet punch, open out the back of the eyelet so it spreads to all sides. (Remember to pad the surface you are pressing against with a bit of lightweight card-board.) Some of the eyelets may split, depending on how smoothly the excess was cut off, how the eyelet is forced open, etc. These split eyelets are still usable; the split will not proceed to the front unless you crush the eyelet very thoroughly after the split starts. After the eyelet has been opened out, you can finish spreading and flattening it with the face of a small hammer.
Measure and mark the placement of the studs on your belt. Make small holes for the studs an awl is better than a leather punch. Press the studs through the belt, check their orientation (so you dont end up with some of them upside down on your belt!), and clip off the excess material, leaving about 1/16 to 3/32 (2 to 2.5 mm.) sticking out of the back of the strap. Using a small crosspeen hammer, peen up the studs, taking a great many small blows 20 to 40 light taps per stud is reasonable. Washers are not needed for these decorative fittings be sure your peening-up forces the metal sideways to make a sort of a flat mushroom.