Turn those old bell-bottomed or flared pants into a straight-legged fashion statement with a few alterations. Skilled sewers will find this task a breeze, although it is a project that anyone with sewing skills can undertake with a little guidance.
Measuring the Pants
Turn the pants inside out and put them back on; button the jeans closed. Be sure that the pants fit well in the waist, hips and rear. Pants that are too big or small or that aren't the right length will not turn out well as straight legs.
Instruct your friend to pinch the outer seam of the pant leg between the thigh and knee where the fabric stops hugging your skin. Secure the excess fabric with straight pins. Continue to pinch and pin all the way down the pant leg. Repeat with the other pant leg.
Take off the jeans and lay them pin side up on a flat surface. With a yardstick, draw a straight vertical line, using the pins as your guide, showing where the new seam will be. The line should go from the hemline up to between the knee and thigh and tapered into the original outer seam. Move the pins about 1 inch from the new seam line, smoothing the fabric in the process. Do this to both pant legs.
Try the pants on again (inside out) to make sure the pant legs are evenly marked and pinned. Because the pants might not have been originally sewn evenly, there is a chance your markings are off. Adjust if needed.
Sewing the Pants
Stitch the pants from thigh to hemline; remove pins as you go. Do the same on the second pant leg. Use your straight stitch presser foot and check your needle size. A regular-size needle will work fine on cottons and polyester fabrics, but a heavy-duty denim needle works better on jeans.
Turn the pants right-side out and try them back on, making sure the seams create the straight leg you want. If they do, turn the pants inside out again and cut off the excess fabric, leaving a 5/8-inch seam.
Finish your seam with a zig-zag stitch, making sure to cover all the ragged edges. Press the seam open and cut any loose strings.
Flatten the seam with your iron.
Make sure you prewash your pants first. You want them to fit well before before they are altered.
Because you cannot go back and fix the pants once they are altered, it is recommended that you have assistance with the measuring and pinning.