Step 1: Measuring and cutting out

Measure the window for the desired width and length of the curtains. For the finished curtain width, measure from one end of the curtain track to the other (adding the length of the overlap arm if necessary). The overall fabric width will be the final curtain width multiplied by 2.
Add 16cm (6.25in) to the curtain length to allow for hemming.
Cut out the fabric.

Tip: Using eyelet headed tape means you can't alter the position of the eyelets, so make sure you make the finished width of the curtains match the positioning of the eyelets, not vice versa. Otherwise you could end up with an eyelet hanging off the end.

Step 2: Finishing the edges

Place material wrong side up. Fold over the long edges 0.75cm (0.3in) to the wrong side and press. Then fold another 1.5cm (0.6in) and stitch in place.
Hem the bottom edge by folding over 3 inches to the wrong side, then another 7.5cm (3in). Press and hand stitch in place.
Finish the top edge by turning under 0.75cm (0.3in) to the wrong side. Press and stitch in place.
Repeat for the second curtain.

Tip: Use a slip stitch to make an invisible hem.