Tatska - or Celtic knot - baskets are probably the most economical baskets to make. Resembling handle-less old-fashioned carpet beaters turned into shallow bowls, they are made out of just thirty six rods of willow. Very much a question of following a pattern and creating hexagons, the instructions include references to tepees and ponds. The secret of success is choosing the materials so that the tension in each rod is the same as they describe their curves to form the rim and the pattern in the base. Different coloured willows can be used to emphasise the way the groups of rods separate and rearrange themselves.