Assemble your supplies. Blue thread and ceramic pencil not shown.

Use the Union Jack in these photos, or search for an image online.

Mark the 2 1/2" x 3 1/2" blue fabric on the horizontal. This is your guide for the first stitching line.

Press fabric to fusible interfacing. Place a piece of muslin or parchment paper underneath to keep the interfacing from sticking to the ironing board.

Set the zig-zag (satin) stitch on your sewing machine nice and wide. You may need to play with your machine a bit to find the right width. Try the setting the machine to the shortest it will go. Stitch following the pencil line. If the stitching seems a little too open, just stitch back over the original line.

For a wider line, stitch on either side of the original line, overlapping slightly.

Your center line should now look like this.

Draw a vertical line across the original stitching line.

Repeat stitching just as for the horizontal line.

Add white stitching around the red lines.

You can also continue with the red stitching and come back to the white thread later later.

Your patches should now look like this.

Add pencil lines on the diagonal as shown.

Add red diagonal lines, outlining in white.

Your patches are going to be a little thick. If needed, fold them into a piece of muslin and press them flat from the front.

I ironed mine to a scrap of muslin so they'd have a smooth back.

Trim the bulgy bits and extra thread from the edges of the patches.

A rotary cutter works great for this if you have one.

Stitch around the outside border with blue thread. This tidies up the edges and stitches down all the loose threads.

All done! Now you can stitch your patch to a bag, jacket or wherever you like!