Gather fabric, lining, interfacing, webbing, zippers, thread, and hardware
Choose a backpack pattern and cut all pattern pieces
Fuse interfacing to the main fabric pieces
Cut foam or stabilizer if the pattern requires it
Mark all notches, darts, and placement lines
Sew exterior pockets and attach closures if needed
Assemble and sew the front panel pieces together
Sew the back panel and attach any padding or laptop sleeve
Install the zipper for the main compartment
Sew the lining pieces together, leaving an opening for turning
Attach straps to the back panel and reinforce the ends
Add top handle, side loops, and any hardware
Sew the exterior panels together
Sew the lining panels together
Join the exterior and lining at the top edges
Turn the backpack right side out through the lining opening
Close the lining opening by hand or machine
Topstitch around the top edge for strength
Attach buckles, adjusters, and strap ends
Press seams and check all stitching for security