Here is a tutorial to make the covered buttons, used in designs such as my Richard the Roundhead Tam, and Scatness Tunic. (These instructions can also be found in my book Colours of Shetland.)
You will need: a plain button with a 1 in / 2.5cm diameter; thin cardboard (eg cereal box), sharp scissors, sharp needle, tapestry needle and a small amount of your choice of yarn.
Select a button with a 2.5cm/1in diameter.
On cardboard, draw a circle 5cm/2in in diameter (I drew round the lid of a spice jar).
Cut out your cardboard disc; measure and mark the centre point with a ruler, and, with a sharp needle, poke a hole through this point.
Mark numbers 1-12, around the edges of your disc, as if drawing a clock face.
With a pair of sharp scissors, cut shallow notches at each of the points 1-12 (notches should be no deeper than 5mm/0.2in)
Take your yarn, cut off a 3ft length, thread your needle, and draw up through the centre of the disc, leaving a short tail no longer than 1cm/0.3in
Draw the yarn across the front of the disc up to notch 1.
Draw the yarn across the back circumference of the disc to notch 12, secure it in the notch, then draw the yarn across the front diameter of the circle to notch 6.
Continue securing the yarn into the notches by drawing it alternately across the back circumference, and the front diameter, in the following sequence:
6 ➝ 7
7 ➝ 1
1 ➝ 2
2 ➝ 8
8 ➝ 9
9 ➝ 3
3 ➝ 4
4 ➝ 10
10 ➝ 11
11 ➝ 5
5 ➝ 6
6 ➝ 12
12 ➝ 11
11 ➝ 5
5 ➝ 4
4 ➝ 10
10 ➝ 9
9 ➝ 3
3 ➝ 2
2 ➝ 8
8 ➝ 7
You have now created 12 front spokes, and 12 back loops.
Draw the yarn from notch 7 to the centre, securing it around the centre of the spokes.
Bring your needle up between spokes 12 and 1 as close to the centre as possible.
Then take your needle backwards over spoke 1, turn forwards and travel under spokes 1 and 12.
Now take your needle backwards over spoke 12, turn forwards and travel under spokes 12 and 11.
Continue weaving in this manner, working anti-clockwise, and drawing the yarn backward over 1 and forward under 2 spokes around the disc. This process wraps and defines the spokes, creating the ridged surface of the button covering. (If you run out of yarn, simply secure the old thread under the spokes, cut a new length, draw it up through the hole at the centre of the circle, and begin weaving where you left off)
When you reach the edge of the disc, turn it to the back, pass the needle under the loop between each notch, and lift it off the disc. Continue around the disc, lifting each loop off in turn, taking care not to let your yarn draw up too tightly.
Remove the button cover from the cardboard disc.
Place the button face down on the back of the button cover.
Carefully pull the yarn, drawing in the button-covering to conceal the back of the button. Make a few stitches across the back, securing, tightening, and neatening the button covering so that the button is completely concealed.
Ensure you retain a length of yarn long enough to secure your button.
Buttons can be made in any size, using your choice of yarn or thread. Just make sure to cut your cardboard disc about 2.5cm/ 1in larger than your buttons. And watch out: once you start turning them out you may find yourself unable to stop . . .