A customer at the quilt shop I work at brought a bag similar to this in to the shop. She explained how she made it and this bag is based on hers.
Gryffindor Tote Bag
BagFabric A (Gold) 7 - 8" x 8"
2 - 6" x 6" (cut in half diagonally to make 4 triangles)
Fabric B (Scarlet) 4 - 8" x 8"
2 - 9" x 9" (cut in half diagonally to make 4 triangles)
StrapsFabric B (Scarlet) 2 - 4" x 25"Lining
Fabric B (Scarlet) 1 - 22 1/2" x 44"
Cotton Batting or Fusible Fleece 2 - 1 1/4" x 25"
*Piece your favorite Harry Potter block. Use any of Jennifer's wonderful patterns on www.sewhooked.org or any 5" finished block.
*Matching center of side of HP block and center of long side of gold triangle, place right sides together and stitch. Press towards gold triangle. Repeat with opposite side of HP block.
*Trim edges even with edges of HP block
*Repeat for last two steps for remaining two sides of HP block
*Square block to 8" x 8'
*Referring to the first picture below, sew a gold 8" x 8" square to a scarlet 8" x 8" square to a gold 8" x 8" square to a scarlet 9" triangle. Make sure the scarlet triangle is positioned correctly. Press towards scarlet fabric. Repeat to make 3. Make another one with the HP block positioned as in the second photo.
*Looking at pictures, sew the bottom of a gold square to the side of the other gold square to make an L shape. Start the seam 1/4" in. Repeat to make 2 total.
*Looking at pic & diagram (you'll need to click on the diagram to get a clearer picture), sew both L shapes together leaving 1/4" open on each sides of seam
*Now take one scarlet point and pull it over the corner of where the gold square is sewn to the scarlet triangle. This will sew one side of the bag together.
*Repeat for remaining 3 sides and turn right side out.
*Lay each 4" x 25" piece of strap fabric right side down on ironing board. Place a 1 1/4" x 25" batting/fleece even with one edge of strap and fold over. Press.
*Fold opposite raw edge over to meet other folded raw edge. Press.
*Fold over to completely encase batting/fleece. Press, pin and stitch to secure edge. Add a stitch or two on each side of first seam. You can use decorative stitches if you would like and your sewing machine has them.
*Pin each strap end to the center of each scarlet triangle. Baste all 4 ends.
*With right sides together and using a 1/2" seam, stitch down one side. On the opposite side, sew a seam leaving an 8" opening in middle of one side. Press bottom folded edge.
*W/bag still wrong side out, line up side seam with pressed bottom edge of lining. Press.
*Measure down from point on each side 7 3/8". Mark on each side and draw a line connecting each mark. Pin & sew a seam on drawn line.
*Repeat for other side and trim off corners.
Attaching Bag to Lining
*W/ bag right side out and lining inside out, place bag inside lining. Pin top edges and stitch together. (I added a zigzag stitch to reinforce the seam.)
*Pull bag right side out through the opening in the side of the lining. Whipstitch opening shut. Place lining inside bag & iron top of bag.
*Enjoy your Hogwarty goodness.
*Just in case your not a Gryffindor, here's how I would do the other houses:
Fabric A - Silver/Gray
Fabric B - Green
Straps - Green
Lining - Green
Fabric A - Brown/Bronze
Fabric B - Blue
Straps - Blue
Lining - Blue
Fabric A - Black
Fabric B - Yellow
Straps - Yellow
Lining - Yellow
pst...I don't own Harry Potter or anything from Harry Potter, JK does.