Fix yourself at a single point where you can observe the horizon at both where the sun rises and where the sun sets.

Determine the points on the horizon where the sun does rise and set - on any day of the year.

Bisect (divide in two) the angle formed by the lines (sunrise to you) and (sunset to you).

The line which bisects this angle will be essentially true south. Note this direction by selecting a point on the distant horizon which aligns with this line, or mark it by some other suitable notation.

If you have a compass, it should agree, after you have taken into consideration any compass corrections.

(The streets in your town may, or may not, run north-south and east-west. Do not trust that idea.)

NOTE: A siting to the sun at 12:00 noon will not likely be true south, especially if your clock is on daylight saving time. Even if on standard time, it will not be true south unless you are located exactly in the middle of your time zone - and your time zone is not distorted due to geographical and population considerations.