There’s an easy way to knit squares on the diagonal - thank you for reminding me. This way you don’t have to decide how many stitches right from the start.
For a garter stitch square.
Simplest method
Cast on 3 stitches using any method you like.
Increase rows
You are knitting a triangle.
Knit 1, increase 1, knit to the end of the row.
Repeat that row until the two sides not on the needle measure 6” (for me this is 45 stitches on the needle)
2 rows straight ( no increases)
Decrease rows
Your rows get shorter to turn the triangle into a square.
Knit 1, decrease 1, knit to the end of the row
Repeat this row until you only have 2 stitches on the needle.
Decrease 1.
You can increase and decrease by any method you know.
Here are simple methods:
Increase 1 - Yarn over, knit 1
or Knit front and back into the same stitch.
Decrease 1 - knit 2 together
Prettier square
Cast on 3 stitches using cable method
Slip 1 with yarn in back (= s1wyib), k1, yo, p1
Increase rows
Every row: K2, yo, k to last stitch, s1wyib
When two sides measure 6” - for me that’s 45 stitches on the needle
s1wyib, knit to end
s1wbyib, knit to end
Decrease rows
K2, yo, s1 K2tog psso, k to last stitch, s1wyib
I’ll check this on Friday or Saturday, it’s past my bedtime now.