Your work space is the foundation for creating your costumes. Keeping things safe and organized will not only save you from potential harm, but will also make your life as a costumer much easier as well! Depending on the space available to you will dictate how exactly you organize your tools and supplies, but there are a few common points you should follow no matter whether you have a permanent sewing room or need to take over your dining room table for a few weeks before each convention.
First, where will you be working? The logistics of your living space will dictate a lot. For most projects you will at least need a place for your sewing machine, a large flat area to lay out and cut your fabric, and someplace to put an ironing board. I keep a table in my office/spare bedroom for my sewing machine and place a cardboard pattern-cutting board on my bed for cutting, and keep my ironing board by the wall so it's not in the way. I've just as easily, however, used a dining room table as a temporary space for my machines and a (non-carpeted) floor to cut, and unfortunately I don't always have the luxury of keeping my ironing board out if I can't keep it out of the way. If you don't live by yourself make sure you check with your roommate(s) or parents before taking over any area for your sewing.
If logistics allow it is important to consider the height of the table(s) and chairs you will be using. If you have the luxury of making your own cutting table make sure it is tall enough for you to work on without bending over too much. Similarly choose a chair that matches the table for your sewing machine well and which has good back support. Keeping these things in mind will help avoid back pain.
Second, and equally important, is where you will be storing your supplies. I like to use a series of tote bins and tool boxes. It's important to keep things within boxes organized, though; for example pins and needles can't just be loose or you might turn your hand into a pincushion every time you reach into your tool box! Pins and needles usually come in little plastic boxes; it's not a bad idea to store them that way. If you have a flat surface or tray to keep it on, you can also use a pincushion or pin magnet. Needles tend to get lost in pincushions, so I like to store them in a scrap of paper or fabric or with a thread through the end. Similarly dangerous can be scissors. If your scissors are loose enough that they'll fall open when not in use, get a screw driver and tighten them (but no so much you can't use them!) or better yet get a sleeve to hold them closed. Take similar precautions for any and all sharp or pointy objects in your sewing kit. Beyond that, the most important thing about your organization system is to figure out something that works for and makes sense to you.
Once you start to sew there are a few standard tips to remember when working with your sewing machine. Read the manual for your particular machine so you know how to properly thread it, wind the bobbin, and set the tension. When pinning garments together before sewing line up the pins horizontally along the edge. This way when you run the garment through your sewing machine your pins are easier to remove, and if you miss one there is less chance it will be hit by the needle. It is safest to avoid running pins under your needle, though, as they can break or damage your needle. If you notice your pins or needles (hand or machine) are looking dull or nicked replace them – a dull needle can more easily break or damage fabric by creating pulls.
Both during and after sewing you need to remember to keep your machine(s) and space clean. Clutter can trip you up, hide sharp objects, and cause you to loose track of things you may need, which is both unsafe and annoying! If a needle of pin falls on the floor ALWAYS attempt to find it so that no one steps on it (speaking of which, it's a good idea to wear shoes whenever in your sewing space). Vacuum or sweep regularly to keep lint, thread, and fabric scraps under control – this is especially important if you have a rolling chair as such debris can clog up the wheels. You should also learn how to properly clean your sewing machine(s), especially if you have a serger as these can get clogged with lint very quickly. If something seems to not be working properly in a sewing machine don't hesitate to take it to a specialist who services and repairs sewing machines. Sewing machines do need to be serviced every now and then to keep them in working order. Sergers and embroidery machines tend to need more frequent tuning than regular straight-stitching machines.
Finally, as with any aspect of safety, always use your common sense. If something doesn't seem right, then take the proper precautions and always spend the time to plan things out and leave enough time that you don't have to rush. Sloppiness causes carelessness which can be dangerous. A little forethought may seem like a waste of time at the start, but in the long run it will save you time and make whatever you're doing come out better, as well as keep you safer.
If you have any questions, comments, or suggestions to improve this article please don't hesitate to contact me!