I do all my own alterations because I'm not a bad seamstress and I'm incredibly fussy when it comes to workmanship. I just recently shortened a calf-length suede skirt. Since suede doesn't need a traditional hem, all you need is a pair of sharp, dressmaker scissors (maybe borrowed from a friend who sews?), a piece of chalk or marking pencil (or wedge of soap, in a pinch), and a measuring tape. I'd check to see if the scissors were sharp enough to make a clean cut by snipping out a tiny piece from an inside seam. If the scissors grab at all, you'll have trouble making a clean cut, so you might have to resort to a craft knife to get a sharp, clean edge.
1. Turn the skirt inside out. Working up from the current edge with the measuring tape, mark where you want the new hem. Use the chalk/pencil (or soap) to make barely visible marks every 1-2 inches. Keep the marks as small and light as possible; you want to be able to brush them off when you are finished. Join the marks with a very light line. You might find a straight edge useful to help make a nice line.
2. Take your scissors (or knife) and cut along the line. Take your time and try to keep your line nice and clean. If you have good scissors, you should be able to cut easily through the fabric. Working with a craft knife takes a bit more skill since you want to avoid jagged edges. Brush or wipe off any residue from the marks and you're done.
If the skirt has a lining, you'll have to turn up the lining and hem as you would any other garment. Fusible mending tape can work if you don't have a sewing machine, since you won't be washing the skirt.
Kate's idea to try this out an inch or so below the eventual hem is a good one if you are unsure. In this case I'd make two sets of marks so that both marks are from the original hem. If you aren't happy with your efforts, your tailor will be able to use the second set of marks as a guide when he/she does exactly what you are doing.
It took me 10 minutes to shorten my skirt, including hemming the lining. Since suede hems are unfinished, they are a snap to do and they don't require any special equipment. If you get a tailor to do this, that's all he or she will do, so I'd be very upset if I was charged more than $10. Now altering the shoulders on a leather jacket-- that's a whole different story!
