I charge time and materials--$15-25/hour depending on where you live and how busy your seamstress is (the busier she is, the higher her rates, usually). Since you don't sew, you will be shocked at how long it can take to sew something that seems quite simple. Roman shades, while a clean, plain look are actually quite a project to make well. Same for chair cushions. Take pictures of EXACTLY what you want made. If you are good at sketching, colored sketches with swatches of the fabrics you want used are acceptable.

Ask her to give you a firm estimate of actual sewing time needed to complete each individual project. By a "firm estimate" I mean an estimate in writing based on the work order (see next item) and a guarantee that you will not be charged for hours over the estimate. I do this with my clients (I'm a professional quilter) and I can usually estimate to within 2 or 3 hours and deliberately estimate high. I keep an accurate time chart and only charge for hours actually spent on the quilt, not to exceed the estimated hours. Once in a while I goof up and someone gets some free quilting, but most of the time, I'm under the estimate by a couple of hours, so they pay a little less than they'd budgeted.

It is fair to set a date of completion, but she's going to be in driver's seat on this one. If she's good, she's busy, and it might be a couple of months before she can get at your projects. It's ok to check in with her a week or two before the agreed delivery date just to make sure that she's on schedule, but please avoid the temptation to call every day until you get your stuff. This just goofs up our schedules because we are talking on the phone instead of sewing. 8^)

Your seamstress will probably have a work order that will be filled out and you will be expected to sign it. Also be prepared to put some money down on the items. I ask for half at the time the work order's approved, the balance due upon delivery. Don't assume that because someone's in business, that they are necessarily a good seamstress-- ask to see some examples of the seamstress's work, either actual items or good, clear pictures.

Keep your receipts for the materials and some swatches of the actual fabrics. I've heard of clients leaving off materials, then claiming that the seamstress substituted something else, because they forgot what they'd delivered to her! This protects both of you.

Annie

Be sure to ask for an estimate first.
Your seamstress will have a good idea of how long the project will take and will estimate this and give you a quote. You may have to pay for extras like lining if you did not provide it.

Best of luck,
Susan

It depends on what you want done? Alterations usually have base price, and change depending on fabric, or linings, etc. I often have people call the shop wanting a price to alter a bridal gown. No way to tell over the phone or even by a picture. There is no way to know before the girl is standing there with the dress on just what needs to be done, Then it also depends of fabric? silk? how many layers, how it's put together, is there beeding? WHEN I am altering formal wear... I first see the girl in the dress, pin fit, then after she has it back off look to see how many layers, how they are put together... For example if I am taking in the sides, IF the waist layers are all sewn together, Much of that waist areas has to be taken loose to even get in and up there... if there are beads, they are removed and re-beaded. (timely and costly)
at my shop, we certainly know how to press, however we only press as to know that the alteration looks great,,,etc. After the work is done and the customer is happy, they take it to the dry cleaners just down from us and have it steamed and pressed.
I've never worked anywhere that some customers didn't complain about prices, just have to ignore it.
I just altered a prom dress for a lady and charged $120. She waited until 4 days before the prom and came in with a heavily beaded dress. OMG. the whole back needed to be remade for it to work. I had to take it home and do it later at night. Started at 9 p.m finished up at 1;40 A.M. She thought it was way to high. I am often way into overtime, that customers think self employed do not deserve lol
Different areas of the country seem to vary in prices quite a bit. I lived in KCMO and prices seemed a bit high in town. I moved back to VA and a lady that wanted me to work for her was charging only$4. pr to hem slacks. WITH a blindstitch, surging off seams...etc... WAY to cheap... Had to say no to taking any of her work.