That tube dress hanging in your closet may have gotten old and boring, or maybe you just need something with a strap or two. If you don't feel like spending bucks at the mall on a spaghetti strap dress, don't go shopping -- instead, make one of your own.
Start with a tube dress. This is a quicker and simpler way than making your dress from scratch. Pick the type of fabric you'd like to use to make your straps. You'll want something durable enough to hold up but pliable enough to work with. Try materials such as cottons and polyester blends.
Wash your fabric to make sure it won't shrink, which would leave you with too-small straps after the first time you wash your modified dress.
Cut your material to your preferred width. How thin or how thick you cut your straps is up to you, but if you want to sport a traditional spaghetti strap, you'll want your width to be rather thin -- think somewhere between 1/2 and 1 inch.
Measure the length you'll want your straps to be using your ruler. Start at the top of your dress and measure up and over your shoulder and down to the top of the dress's back. When cutting your fabric, make it a bit longer than your measurements to leave room for error.
Fold your straps lengthwise. To make one sturdy strap, sew the loose ends of your fold together so that you've formed a "tube." This means that you'll be sewing down the side opposite of the fold. You'll want to start from the top of the fold and work all the way to the bottom.
Turn your spaghetti strap right-side-out, so you won't be able to see the seam. To do this, use a safety pin. Fasten the pin to one side of your tube and push inside and all the way through the strap. Once you've reached the other side, the strap will be turned right-side-out.
Pin your straps to your dress with a safety pin to tell exactly where they should be sewn on. Stitch your straps onto your dress using thread that's the same shade as your dress. Make sure to stitch them on the inside so the stitches will be less visible. You now have a spaghetti strap dress.