A large, washable diaper bag that holds all of baby's essentials in an organized manner makes your life easier. You only need basic sewing skills to make an inexpensive, durable diaper bag that you'll enjoy using or giving as a gift. You'll be so pleased with your results that you'll want to make several bags in a variety of colors or patterns. You might even decide to start your own business making and selling these diaper bags.
Wash and dry the cotton fabric to preshrink it. Iron it.
Use a pencil and tape measure to draw a large rectangle 35 inches by 17 inches on tissue paper for the body of the bag. Draw a square 14 inches by 14 inches for the flap. Draw two smaller rectangles 14 inches by 8 inches for the inner pocket. Draw another rectangle measuring 30 inches by 4.5 inches for the carrying strap. Cut out all pieces.
Lay the outer-bag fabric, single thickness, on a large, flat surface. Smooth out the fabric. Pin the pattern pieces for the body of the bag, the bag flap and the carrying strap on the fabric, aligning one of the long sides of the large rectangle with one of the edges of the fabric. Trace around the pattern pieces using fabric chalk. Remove the pins and tissue paper. Cut the fabric along the chalked lines.
Repeat Step 3 with the lining fabric but omit the pattern for the strap and use the two pocket pattern pieces.
Lay the large rectangle and square of outer-bag fabric on the work surface with the wrong sides facing you. Lay the interfacing on top of the fabric with the glue side facing down on the fabric. Fuse the interfacing to the fabric by ironing with the iron set to a low temperature or follow the interfacing manufacturer's instructions for application.
Lay the large rectangle section flat on the work surface with the right side facing you. Bring the two shorter ends together, folding this section in half, forming the body of the bag. Pin in place on the two sides, leaving the top edges open.
Thread the sewing machine with colored thread that matches the outer-bag fabric. Stitch along both side seams of the bag leaving 1/2 inch seam allowance.
Lay the bag on the work surface with the wrong side facing you. Lift the bag by the top edges and stand it up. Create a flat bottom for the bag by inserting your hand inside the bag and pushing out the bottom corners to form two triangles. Pinch off the triangle at each bottom corner and draw a 4-inch diagonal line across the corner. Pin in place. Stitch across each corner to form the squared off bottom. Do not cut off the excess fabric in the corners.
Fold over 1/2 inch on the remaining raw edges on the top of the bag towards the wrong side of the fabric. Pin in place and iron. Stitch.
Fold over 1/2 inch towards the wrong side on three sides of the interfaced square section for the bag flap. Stitch in place.
Turn the bag so the right side is facing you. Lay it flat on the work surface. Attach the unfolded edge of the interfaced flap from Step 10 to one of the top edges of the bag. With the wrong side of the flap facing you, slide the rough edge into the bag so the edge overlaps 1/2 inch. Center the flap on the bag's edge. Pin in place. Stitch along the rough edge, about 1/8 inch from the rough edge. Stitch again about 1/4 inch from the first line of stitching.
Repeat Steps 7 through 11 using the lining fabric.
Lay one of the pocket pieces on the work surface with the right side facing you. Lay the second pocket piece on top with the wrong side facing you. Pin in place around all four edges, leaving a 3-inch opening on the last side. Stitch. Turn the pocket section inside out so the right side faces you. Fold in rough edges 1/2 inch toward the wrong side of the opening. Stitch in place.
Turn the bag lining so the right side is on the outside facing you. Place the pocket section on one side of the bag lining. Place the longer edge of the pocket section parallel to the bottom edge of the bag, about 4 inches above the bottom fold of the bag lining. Pin in place.
Stitch around the bottom and sides of the pocket section, about 1/8 inch from the edge, leaving the top open. Stitch an additional two straight parallel lines from the top of the pocket section to the bottom to create three sections within the pocket.
Fold the fabric for the strap along the long edge with the right side of the fabric on the inside. Pin in place. Press with the iron. Stitch along the long edge. Insert a safety pin into one of the short open ends of the strap and push it all the way through the tube to turn the strap right side out. Press flat.
Place the outer bag on the work surface with the right side of the fabric facing you. Place one short end of the strap on the inside of the bag centered on one of the side seams, about 1 inch below the top edge of the bag. Pin in place. Stitch about 1/8 inch from the top edge of the bag. Stitch again 1/2 inch from the first stitching. Repeat with the other end of the strap on the other side of the bag.
Turn the bag so the right side is facing you. Turn the lining section so the wrong side is facing you and the right side with the pocket section is on the inside. Insert the lining into the bag aligning the top edges of the bag and the edges of the flap. Pin in place. Stitch all around the edges, about 1/8 inch from the edge. Stitch again 1/4 inch from the first stitching.