The relaxed and open look of gaucho trousers come in and out of fashion over and over again, but the comfort of gaucho trousers never changes. While you can find gauchos off and on in departments stores, they can be made with three pieces of fabric and a sewing machine for much less. Choose an apparel fabric that flows with you, such as knits or linen, and pick a colour that can be enjoyed for years to come.
Measure and write down the width around your waist, the width around your hips, the length from your waist to just below your knee, and the width around your upper thigh. Measure also the length from your lower back between your legs to your belly button.
Fold your fabric in half lengthwise and lay it on a flat surface with the fold running horizontally along the bottom. Using the fold as one side of the box, draw a rectangle with the long side running parallel to the fold equal to the distance from your waist to below your knee. Make the width of the rectangle equal to half the measurement around your thigh.
Place your tape measure along one of the top corners (where the fold isn't) and allow it to curve inward on the rectangle by half of the measurement from between your legs. Trace the curve of your tape measure to form a crotch portion for your large rectangular pant leg.
Draw a second rectangle the same size as the first further down on your length of fabric, keeping the fold of the fabric as part of the rectangle. Add in the crotch line curved portion. Cut out both rectangles a 1.2 cm (1/2 inch) outside of your drawn lines.
Draw on your remaining fabric and cut out a strip eight inches wide with a length equal to your measurement around the hips plus one. Cut out this narrow rectangle on the drawn line. Set this piece aside for later and remove the remaining fabric from your work space.
Pair up the long edges of one pant leg with the right side of the fabric facing in, pin the edges and sew along the straight line, leaving the curved portion unfinished. Repeat for the other pant leg, also leaving the curved portion unfinished.
Align the curved crotch portion of the two pant legs together from one side of the trousers, scooping downward, and to the other side. Pin and sew the crotch closed, adding backstitching at the intersection of the leg seams when you reach them.
Align, pin and sew the short, 20 cm (8 inch) sides of the piece of fabric you set aside to form a loop. Place the loop inside the top opening of the trousers with the right sides facing one another. Align, pin and sew the top edge of the loop to the trousers all the way around.
Fold the loop up to form the waist band of the trousers. Create an open hem in the top of the pant by folding the fabric down twice by one inch each time. Sew the hem all the way around, leaving a 5 to 7.5 cm (2 to 3 inch) wide gap in the back.
Cut a section of elastic to the length of your waist measurement. Snake the elastic through the hem opening in the back. Overlap and stitch the elastic ends together once it is pulled through the waist band. Tuck the elastic ends inside the hem opening and stitch the opening closed.
Fold the bottom edge of the pant legs to create hems just as you did with the waist portion and sew in place. Turn the trousers right side out to finish.
Using a serger or sewing with a zigzag stitch can help avoid fraying and seam opening over time. To check your measurements before you sew with your expensive fabric, try making a pair of gaucho trousers from muslin or another cheap material as a test pair to see how you like them.