You’ll need to cut 2 of each of these pieces (click on the pic to enlarge it to a readable size).
The measurements are in centimetres because that’s the way I was brought up (sorry). A seam allowance of 1cm is included in these measurements.
This basket’s base is 15cm wide, but you could make any size using this slightly haphazard formula, where x is the width of the base and y is the height of the basket. And 2 is cm and seam allowance.
Pieces cut, sew right sides together along these seams:
Sew the boxed corners of the linings by folding the pieces open, matching the side seams with the bottom seams, and stitching across:
Zig-zag the top edge of the smaller lining piece. Turn the smaller one right side out, the bigger one wrong side out, and put the bigger one inside the smaller one. Match up the corners and the side seams, then stitch them together along the top edge of the smaller one.
Hem the bottom edge of the outer sleeve piece, turning up 1cm all round and stitching it down.
Turn the lining pieces so that their right side faces out, and slide the outer sleeve over. Stitch together (right sides together) along the top edge:
Almost done, except for the fiddly part! Turn the whole basket inside out, pull the outer sleeve out, fold it down along the seam line, and topstitch along the top edge. (This makes sense when you do it - not so much in your head, trying to imagine it.) The topstitching isn’t crucial, but makes the next step easier.
Matching up the side seams, pin the outer sleeve to the lining. Now stitch from the top to as far as you can get towards the bottom, on each corner. This is the fiddly part, by the way. Mark and pin in any way that seems sane to you: disappearing pens or chalk are good.
See the stitching on the corner? It doesn’t go all the way to the bottom, but close enough. Measure the pockets, cut 4 pieces of card to fit, and slide them in:
If you used the same measurements I did, the card should be about 14 or 15cm by 11cm; cut slightly bigger than you think, and trim down.
There’s a way to avoid the fiddly sewing bit, of course! Instead of sewing corner seams, sew the lining to the outer sleeve along the side seam lines. Then the bits of card need to look like this:
Still a sturdy basket, and almost just as neat.
Play around with heights and widths for different uses; make the lining and outer from the same fabric, just doubling the height measurement for the larger lining piece.