Notes: General stitch length is 2.5cm, and will be used unless otherwise indicated (for gathering purposes) and the general seam allowance is 1cm and will be used unless otherwise stated.
Step One: Lay out the fabric and identify the right side and grainline (which is usually parallel to the selvedge). Place the pattern pieces on the fabric according to the grainline. It is also important to match up the pattern pieces with the patterns on the fabric and to place the pieces all in the same direction of the fabric so it all lines up properly. Make sure to read the cutting instructions on the pattern piece to see if it is cut on the fold, or cut one single so you can place it appropriately.
Step Two: Trace around the pattern pieces with tailor's chalk, and cut out the pieces. For this garment, there will be a pair of fronts (one left and one right), a pair of backs (one left and one right), and a pair of waistbands (these need to be cut separately because they are curved so they cannot be cut on the fold).
Step Three: Cut out fusing pieces and fuse the relevant fabric pieces, which in this case, are only the two waistband pieces. Pin the two waistband pieces with right sides together and plain sew the top edge. Turn it over and press the seam allowance flat to one side. Understitch on the right side to keep the seam allowance to one side. Press.
Step Four: Using a plain sewer machine and appropriately coloured thread, pin the dart placement for one of the fronts and sew the dart. Repeat this with the other front, and press the darts flat towards the side seams instead of the crotch. Pin the dart placements for one of the backs and sew the two darts. Repeat this with the other back, and press these darts flat towards the side seams again.
Step Five: Pin both of the fronts together with the right sides together at the crotch area. Plain sew the crotch lines together from the top of the centre front to the bottom of the curve. Repeat this step for the backs. Measure the length of your chosen zip (for this garment I used a 29cm concealed zip that will be going in the left side seam). Measure the depth of the waistband in conjunction with the length of the side seam (removing 1cm for a seam allowance). Mark the point of 29cm with tailor's chalk. Overlock the crotch seams and then press them smooth. Lie the two fronts on a table with the right sides facing upwards. Place the two backs on top so that fronts and back are connected with right sides together. Pin together at the side seams on the right side to the lower notch, and the crotch points as well as the entire inner legs. Plain sew the pinned side seam to the notch. Plain sew from the marked notch to the lower notch hem on the other side seam. Plain sew the inner legs, making sure the central crotch lines match up. Press the seams smooth and flat.
Step Six: Turn over one open side seam 5mm and then another 5mm, using the same sort of process as a rolled hem. Pin it to secure. Topstitch the entire pinned section to the unfinished hem edge. Press this flat and smooth. Check all of the inner seam allowance was caught, and fix if not. Repeat this process for the other three open side seam allowances.
Step Seven: Pin the fused side of the waistband to the top waist area of the culottes, starting at the left side seam and ending at the left side seam to ensure the waistband fits the garment waist. Plain sew with a 1cm seam allowance. Turn the waistband up and press flat. On the inside, press the seam allowances up towards the waistband. Turn the top half of the waistband down to the inside, and press a 1cm seam allowance so the finished edge matches the pressed up seam. Pin this in place over the entire length of the waistband. Topstitch on the outer side of the trouser all the way around the waistband. Remove the pins and check that all the inner seam allowances have been caught and sewn down, if not, unpick the section and resew.
Step Eight: Press the waistband smooth. Take the concealed zip and line it up with the left side seam on both sides. Fold one side of the zip so the garment and zip right sides are together and the wrong side of the zip is facing upwards. Change the sewing machine foot to a concealed zipper foot. Line up the zip and plain sew as close to the zipper teeth as possible. Repeat these steps with the other side of the zip. Once the zip is in, check to see that it works and runs smoothly. If there are any issues, fix them at this stage. Press the seam allowances and zipper tape place from the outside.
Step Nine: Pin the hem of the trouser at the chalked line so the outside shows the desired finished edge. Try the trousers on a model or the person that will be wearing them to see if the length is suitable. Turn the trousers inside out and do a rolled hem. This involves turning the raw edge under 1cm and then rolling the fabric over until it meets the marked length. Pin this in place and plain sew on the outside to secure. Give the garment a thorough press in all areas.