Large Pavers..,....I mean
LARGE!!
Like 500mm x 500mm, 600mm x 600mm, or LARGER
Then there is no need for anything else;
let the grass grow up to and around them.
OR if they are Hexagnal or Octagonal,
then you could butt them so that when you walk, it's
Left, Right, Left, Right, Left, Right, Left, Right.............

Size and
spacing has to be pretty Spot on though