Knitting your own clothes allows the garment to be custom-made to your specifications, resulting in a perfect fit. Common patterns may be modified by varying the pattern of the stitch as well as selecting from a variety of coloured wool. But even experienced knitters sometimes have concerns about how to sew their finished garments together. Learning a few basic principles will make the process much easier to master.
Block the knitted sections of the jumper by laying each piece flat on the iron board. Cover each section with a damp cloth and press with a warm iron to steam them into shape.
Place the back section of the jumper on top of the front section with the right sides facing each other on the inside. Align all the outer edges. Place pins every 2.5 cm (1 inch) along the side seams and shoulder seams.
Thread one end of a length of the wool used to knit the jumper through the eye of a knitting needle. Start at the bottom edge of one of the side seams and take a stitch by piercing both knitted section of the jumper close to the edge. Pierce the fabric through several times in the same spot to secure the wool. Insert the needle through both sections again to start a stitch. Pull the needle firmly through to the other side, but keep the seam flat.
Insert the needle through both sections of the jumper bringing the point through to the first side, forming a stitch of about 6.5 mm (1/4 inch) long. Pull the needle up and through the jumper sections. Take a backwards stitch by inserting the needle 6.5 mm (1/4 inch) back from where the needle emerged from the fabric. Bring the needle back up to the front of the seam, having the needle emerge about 3 mm (1/8 inch) further along the seam, past the point where the wool emerged from the previous stitch.
Continue sewing along the side seam with these "back stitch" stitches until you reach the top of the side seam at the armhole. Take several stitches in the same spot to bind off the wool.
Repeat these steps to complete the other side seam and both shoulder seams. Remove all pins.
Take one of the jumper sleeve sections and fold it in half lengthwise, aligning all the edges and with the right side folded inside. Pin in place. Start at the cuff edge and sew the arm seam up to the underarm, using the back stitch. Securing the ends of the wool as done on the side seams. Remove the pins. Repeat for the second sleeve seam.
Turn the sleeves inside out so the wrong side is facing you. Insert one of the sleeves into the armhole, with the right side of the sleeve touching the right side of the jumper and the top edges of the top of the sleeve aligned with the armhole edge. Align the seam of the sleeve with the side seam of the jumper. Place pins around the armhole edge.
Stitch the sleeve in place, working the stitches the same as you did for the side seams of the jumper. Bind the wool to secure it at the end of the seam, when you complete the circumference of the armhole and meet the point where you started sewing in the sleeve. Remove all pins.
Repeat to sew the second sleeve into the second armhole. Turn the sleeves and the jumper right side out.
Do not pull the stitches too tightly as you sew. Maintain a firm tension that does not alter the length of the jumper's seams without stretching the seams or pulling the stitches too tightly, which would make the seam slightly shorter.
Alternatively, instead of the "back stitch," you might wish to use a "mattress" stitch for the seams. The mattress stitch is sewn by laying the two pieces that are to be joined side-by-side with right sides facing you. Insert the needle under the horizontal bar that is found between the first and second stitches from the edge of the knitted section. Insert the needle into the corresponding bar on the other section. Continue pulling the wool through the corresponding bars until the pieces are sewn together.