1. A Notions Gift Bag - Seriously, this is my number one suggestion for a gift for anyone who sews on the regular. Just go to the aisles of your local fabric store that sell thread and zippers and needles and snaps and bias tape and grab... anything. I promise you, it will get used. I am forever needing invisible zippers and sewing machine needles (just get the universals). And if you want to get really fancy and/or spendy you could purchase around a theme such as putting together a collection of cutting tools. Grab a pair of Gingher Dressmaker's Shears (currently on sale at Joann's), a rotary cutter, applique scissors, and embroidery scissors and you have a flawless present! Seriously, a girl can never have too many high quality scissors.
*Special Tip* - Buying yardage of fabric can be risky... but if you can't resist (sometimes you see a great deal on a print that really sings!) buy at least 3 yards, 4 is better. Actually this is a good rule of thumb in general as even when I purchase fabric with something specific in mind, these things tend to change and it is sad when you realize the 2 yards you bought for a blouse would actually make a perfect dress that requires 3.5. Avoid my mistakes, young shopper...
2. Magazine subscriptions - a great last minute gift that keeps on giving. Gift subscriptions for many sewing/knitting/crafting magazines are easily accessible via the interwebz but if you want to do things the old fashioned way (and give your recipient a present to open under the tree) pop by your local bookseller and pick up the most recent issue and add a note that you've filled out the card to purchase a full year of glossy gorgeousness. My favorites are Threads and BurdaStyle.
3. Books - While you are at the bookstore picking up your sewing based magazines you should also peruse the selection of hard copy books. My favorite references include anything by Claire Schaeffer, Fit for Real People, and (if you are shopping for more of a beginner) the Colette Sewing Handbook. And even easier, all these options and more are available at Amazon. Speaking of Amazon...
4. Purchases from Amazon - There are four days left to order from Amazon to guarantee delivery by Christmas... usually with free shipping! Now I don't know about everyone else, but I certainly have a broad selection of sewing based items on my wish list. Many of your intended gift recipients may have a standing wish list and you can search for your friends and family by name or email. Some of my favorite items on the list include this form curve ruler, pattern books, and notions such as That Purple Thang. An excellent gift for a beginner sewer might be a basic machine, I recommend the Brother CS6000i. I owned this inexpensive machine for several years of hard use and it held up beautifully. It is a great gift for someone who thinks they may be interested in picking up the best of hobbies, but is not yet committed enough to lay out the big bucks.
5. Gift Cards and other vouchers - Now the gift card can tend to the impersonal, but they are also always appreciated and a store specific card chosen will care can be surprisingly thoughtful. Some ideas for gift vouchers include: Mood, Britex, Joann Fabrics and Craft Stores, and FabricMart. And of course, as mentioned above, Amazon.
Of course, when time is not of the essence, there are so very many more options! You can get suit making kits from B.Black & Sons! Tapestry kits from the Liberty Haberdashery! Japanese Hand Sewing Needle sets! Knitpicks! Pattern Drafting Rulers! A high quality iron! (I actually really need that last one... can someone forward this to my boyfriend?)
In any case, my point is that when shopping for a seamstress, the possibilities are endless. So go forth, go shop, and if you do a good job there may just be some homemade goodies for you under next year's tree!