You name it I got a shortcut for it! First-timers should always go by the instructions. These are techniques for the more experienced, and for those willing to take risks.
Gathering!

Instead of doing as the instructions say, where you're supposed to use the the longests stitch on your machine (usually 4), you take a piece of string, or crochet thread, and zig-zag it onto the material...and pull the string, instead of the thread.
Cross-stitching!

To find the center: instead of sewing the threads across, just fold the material and mark it with a pen (a crafts pen, that washes out, or erases) This saves you about 5-10 minutes, during which, you could be starting your first line!
Cutting!

Instead of following the cutout layout provided with your pattern, try having all the paper pieces out, and laying them out so that they fit as close as possible (this may take some experimentation) before you begin to pin down, and cut. This can save you a large amount of fabric, (usually at least half a yard!). If you are on a budget, this technique will usually save you a bit of money, or at least save enough fabric for some matching accessories. On stripes and diagonals, this method may not work. On solids and continuous patterns, it works very well.'
Scraps!

Scraps are useful! Never throw out even a stitch! You can collect useless scraps of fabric in a bag, for stuffing. Larger scraps can become intregal for dolls' eyebrows, sock-puppets, home-crafts, for your children, or school donations. Throw nothing away! Keeping your trimmings in a cheap plastic bag can save you many dollars, later. Keep the buttons, even if you throw away the shirt! Save scraps from throw-away clothes, too.. An old pair of jeans can become patches for a newer pair, or even a stylish jacket!