This necklace was made for £1.25 using 1 meter of thong (45p from a haberdashery shop) and the buttons (from Wilkinson) were 80p for the pack. This made 1 necklace.
The photos show that I have simply threaded the buttons on using two opposite holes of each button going up through one hole and down through the next one. Once the thong is pulled tightly the button is secure.
Alternate the size and colour of the buttons on each side of the thong. It doesn't matter which way the buttons are facing and you don't need to have equal gaps between them. The haphazard placing of the buttons leaves the necklace looking beautiful from every angle. If you perfectly positioned the buttons then the necklace is likely to have only one side that looks good.
One you have created two 20cm lines of buttons then knot the bottom together as close to the buttons as possible.
Then tie a bigger button onto the bottom of the thong to cover up the knot.
To finish the necklace add a few more buttons to the bottom of each end of the thong and once you are content with the length of the necklace tie the ends and cut.
These necklaces used to cost £15.99 in White Stuff. It cost me £1.25 and about 10 minutes to make.