An easy project and cheap as.
Here’s an offical picture off the net thanks to Wikipedia. I left my king at 4*4 rather than cutting down to 90*90 mm. Bowls here are round. Fancy sets are on line for big bucks mad out of hardwoods etc but research suggests weights used generally mean pine is most suitable.

I purchased some dunnage from the timber yard at Bunnings which conveniently is close in dimension for the ten Kubbs.
The king was made from 4x4 the bowls from dunnage cut down to size and I like the octagonal look. Technically dowel is used but quite costly.
You could if you want belt sand these round but the family don’t care.
Two stakes to mark the centre line and four corner stakes - oh and I threw in a hammer made from scrap - not essential.
All you need now is a lawn park and a few beers and sausages.
A typical set
There are typically twenty-three game pieces used in kubb:
- Ten kubbs, rectangular wooden blocks 15 cm tall and 7 cm square on the end.
- One king, a larger wooden piece 30 cm tall and 9 cm square on the end, sometimes adorned with a crown design on the top.
- Six batons, 30 cm long and 4.4 cm in diameter.
- Six field marking pins, four to designate the corners of the pitch, and two to mark the centreline (though the last two are often missing).