Think of the overall picture as being made of:

a single length and turns of 45 degrees or 90 degrees
or
one large square and smaller squares, the lengths of whose sides you need to choose
or
small squares (you can draw one square, and the next, and the next, but where do you start each time?) and then the large square.

How about having a base length of 20 and start by turning through 45 degrees, something like:

RT 45
FD 20
FD 20
FD 20
FD 20
LT 90 ...

What am I drawing?