This is not too difficult but works out brillianly .
All you need is an old piece of wood (mine was 38 cm by 50) , hammer and small nails or tacks , brown paint and some coloured embroidery thread.
1) paint the old wood brown, both sides .
2) leave to dry .
3) cover your board with one piece of news paper and draw a shape on it . GO OUTSIDE (to prevent holes from being smashed into your expensive kitchen table , like my sister did) and hammer nails into your board using the shape as a guideline . leave a one cm gap between the nails .
4) pull out the newspaper from under the nails and admire your amazing hammering skills.
you are done !