There are three categories of sewing machine stitches: straight, zig-zag, and decorative. Just about any brand and every price point of machine can do all of these. Even the least expensive ones have at least a few decorative stitches.
By far, the most commonly used stitch is the straight stitch. You’ll use this one probably 90% of the time. It sews seams together, stitches up hems, sews on trims and can even be used to do fancy embellishments like pintucks. The good old straight stitch will be your stand-by for just about every sewing task.
The straight stitch does have some variations though. You can change the stitch length settings on your machine to make stitches very close together for a tight secure seam. Alternately you can set it to the longest length to make a basting stitch. This stitch is a lot looser and can be pulled up to make gathers. Basting stitches are also easy to pull out, so they’re used when you want to hold seams together temporarily.
Your machine also has a zig-zag stitch. Zig-zags jog the needle back and forth to make a line that looks something like a row of z’s. You can use this kind of stitch to finish seams, add a decorative touch to pockets or hems or attach elastic or stretchy trims. A really close zig-zag can be applied to the edge of appliqué to hold it in place on top of another piece of fabric too. Stitch length and width settings give this stitch lots of variations. You can make a tiny tight line of zig-zagging which will hold tighter or you can make a long loose line of zig-zags that will provide more stretch to the fabric.
Finally, the decorative stitches give you something fun to play with. They are totally unnecessary, but they add a little joy to a project like jam adds joy to toast. You may want to add some decorative stitching to the top edge of a pocket, the ruffle of a pillow cover, or you can even stitch a row or two on some clothing you already have to give it a little extra zing.
Decorative stitches are never used for seams. You’ll only use them for top stitching. And don’t feel limited to one row either. You can combine rows of decorative stitches to make all sorts of designs. This is where the creative fun kicks in, so feel free to experiment.
These settings can be accomplished in various ways, so check your owner’s manual to see how to select your decorative stitches. You may need to tap a touchscreen or set a dial, but your manual will show you how they will look and how to choose them. They come in all sorts of shapes and can also be modified in length and width like zig-zag stitches. Some decorative stitches look like garlands of flowers or clovers. Others are more geometric like something you’d see on an ancient Greek vase. Generally the more expensive the machine, the more choices you’ll have for decorative stitches.
So go ahead and try out all the stitches your machine has to offer. Use up your scraps of fabric or chop up some old clothes to practice on.