Back to (almost) basics.......

New month, new twist on the basic granny square!
Today's square is worked from the corner using the same stitches as in a basic granny square but only working two sides of the square:

I have changed colour after every row to try and accentuate the pattern and as is often the case I have finished it off with a round of double crochets.

Chain 6, join with a slip stitch.
Chain 3, 3 treble crochets, chain 2, 4 treble crochets into ring, finish off thread.
Join new thread on same corner as initial 3 chains, work 4 chains, 3 treble crochets, 2 chains, 3 treble crochets in the corner space, chain 1, 1 treble in the top of final treble from previous row, finish off thread.
Join new thread into 3rd chain of the initial 4 chains in previous row, chain 3, 3 treble crochets in chain space, chain 1, 3 treble crochets, chain 2, 3 treble crochets in corner space, chain 1, 4 treble crochets in final space, finish off thread.

Repeat last 2 rows, increasing as needed until the square is as big as necessary.
(NB - the round of double crochets are worked over the 4th treble crochet or the 3 chains on the outside on two of the edges and in the top stitch on the other two edges.....)