Then cut out 5 pieces for the sides and the bottom. In this instance, I cut:
a 380 x 130 mm piece for the bottom
2 450 x 380 mm pieces for the front and back
2 450 x 130 mm pieces for the two sides.
(This left plenty of overlap as the finished bag was 400 mm high, by 350 mm wide and 100 mm deep)
Then sew together your pieces, sew the inside side of the material (so when you look at the patterned surface, the seams are on the inside). Sew all of the sides onto the bottom first checking that the edges will be nice and straight. Then you can sew each edge. I sewed by hand, but you can machine-sew this (I just don't have a machine that works very well)
Then tidy up each seam with a blanket stitch, fold the excess material over as you stitch to produce a neater result.
Fold these over and iron flat, ensuring that all of the frayed edges are folded inside, pin it until you are ready to sew..
Then sew the edges together.
Then sew your handles to your bag. To create a nice finish, fold the end of the handle over to hide the frayed edge. Measure from the edges of the bag to ensure that you get the handles central.
Then pin the handles where you want them. Before you sew then on, hold the bag by the handles to check that they look central and that the bag doesn't drag on the floor as you walk.
Then sew them on. Bear in mind that the handles will take the bulk of the weight of the bag contents, so make sure that you sew them on well.
This made a nice present (as well as bag for other presents) for my Mum's birthday :)