Besides fabric, your tools are the most important thing you need to make sure your project is going to come out correctly. I have amassed these as I've gone along, somehow managing to make wonky Halloween costumes and curtains along the way. If you pick up a learn-to-sew book, you will find a laundry list of tools that they recommend you have, so I tried to keep it to the items I use the most on a regular basis. Most of these can be found in your local sewing store, and with a coupon you can score a great deal.
These mats come in a variety of sizes but are fantastic for a few reasons. They save your tabletop from nasty cuts and gashes (they are great for both fabric and paper cutting, by the way), and they are also printed with a ruler along each edge and squared up so you know your edges are straight. Because the mat is self-healing, any digs you make in it with your scissors, cutter, or pins blends right back in. The squared ruler is basically a more rigid version of the mat, with intervals marked out. Because it is clear, you can place it on top of your fabric to see what you'll be cutting and to make sure it's square. Neither of these are dire, but they sure do make cutting fabric straight easier.
There are many different types of thread. The most common thread you will need for most simple projects is all-purpose thread. It's tough, it's durable, it's cheap, and it comes in a zillion colors. Specialty threads are just that: for specialty projects. So unless you are getting fancy or doing a very specific task, all-purpose thread will serve you well to start out.
a.k.a. Your new best friend. A seam ripper is the best tool for undoing sewing that you've already done when something turns out wrong. The inner curve is a blade that will cut apart your stitches. Slide the sharp edge under a flat stitch or in between a seam so the threads reach the blade, then push it through until the stitches pop. Repeat until you've undone whatever mistake has come to be. Pray that you don't need to use this one too often, but more likely than not, you will.
Great for holding layers of fabric together. I have said before that I am not a great pinner. I am rapidly taking that back and using my pins whenever I need to. They come in various lengths and sizes good for holding together various thicknesses of fabric.
These are your sewing machine essentials. Bobbins hold the thread that will become the bottom thread in your stitch. It can be the same color as your top thread or different, depending on the fabrics you are using. Bobbins fit into a slot under the machine, and they never, ever hold enough thread. You will also realize that no matter how many bobbins you have, you will never have enough for all the colors of thread you will accumulate.
Sewing machine oil is new to me, which is a big mistake. Your sewing machine's moving parts should be oiled every 20 hours of sewing, according to the kindly Russian gentleman who recently fixed my machine for me. The oil keeps the moving parts sliding along smoothly, which is definitely a good thing.
Sewing machine needles are generally universal fit needles, though you have to be careful that they will fit your brand. I have been using Organ needles, which I order online, but you can find universal needles in any sewing shop. They come in various sizes for various thicknesses of fabric. Size 90/14 is the standard needle size. This is good for most sewing projects. The larger the number the greater the fabric thickness, and vice versa. I keep some 100/16 needles on-hand if I'm going to be doing something with a lot of weight to it. Also be careful when sewing: sewing machine needles can break at any point, including while you are sewing, so please be careful of flying needle parts. I have had more than one hit me in the cheek. I try to remember to wear glasses when I sew.
Great for measuring, and the flexible kind are good if you have non-rigid things to measure, or in small spaces while sewing on the machine.
A new favorite! Obviously it's good for delinting your fabric, but it's even better for picking up threads on your cutting and sewing surfaces, and the ironing board cover. (See above.)
Ask a serious crafter and they will tell you that they have sewing scissors and paper scissors and never the two shall mix. Good fabric scissors have a straight, flat bottom so you can easily slide them along a tabletop without making an angle. (The middle pair.) They come in various sizes and blade types. I like Fiskars brand because I think they make a good sturdy tool. A pair of thread scissors are good for keeping at your sewing table to snip threads as you go (On the right). I also recently got a pair or pinking shears, which make a zig-zag edge and help fabric from unraveling (On the left and see below).
Rotary cutters are awesome. It is basically a rolling Exact-o blade and it is awesome for laying our a large piece of fabric and cutting a big long piece. The larger roller is good for large pieces and the smaller one for smaller pieces. These are probably the most useful tools I've bought thus far (and they're great for paper too!).
Pinking shears blade
Also necessary- an iron and ironing board. There are super-duper fancy irons out there but in my sewing room I keep an old Black and Decker that heats up instantly and works perfectly for my sewing projects. I have a tabletop ironing board stashed in the closet so I can just set it up whenever I'm ready to work. It's handy having one right in my workspace.
In order to continue along with me, I would suggest you have a pair of scissors, pins, some sort of ruler, a seam ripper, and your sewing machine parts- bobbin, thread, and needle- ready to go. Homework this week will be to find and collect those, along with some kind of remnant piece of fabric- preferably cotton and non-stretchy. Nothing fancy, just a piece of scrap that's maybe 8" x 8" so we can play around with stitches.
I hope you'll come back and stick around with me, and also leave some feedback of whether this has been helpful to you or not. I'd love to hear what your favorite tools are and let me know if there's something on your list that's not on mine!