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If you have your laptop out with you then finding south is easy. Use Stellarium and place the south cardinal point at the bottom of the screen. Zoom so you get a slightly curved horizon. Turn on the Alt-Az grid.
Now see if there are any stars slightly west and below the South Celestial Pole on the screen that you can also identify in the sky. Use triangles of stars to help you make sure you have a match. Once you’ve picked a suitable star all you have to do us wait for that star to be on the vertical 180 deg. azimuth line. This is the meridian. It will cross right to left below the SCP and left to right above the SCP.
You can speed things up in the app by using the time forward button and pause when the star is on the meridian. Note the time. All you have to do is then is see where that same star is at the time noted in the real sky. It will be on the meridian. Drop avertical line to the horizon and that is true south. Works for any star south of zenith (for finding true south) and north of zenith for finding true north (motion reversed). The star must not yet have crossed the meridian otherwise pick another star but not one too far east or west or you’ll be waiting a while. Works for the Sun too at solar noon. In winter the Sun is lower in the north and finding true north is easier as the plumb line is shorter True south is simply 180 deg. from true north if using this method in the day.
I used to use to Sun shadow method but I find the app method easier and quicker. Works great for Venus too in the daytime when it’s not too close to the Sun. Simply find when it crosses the meridian and then go look for it at that time. You’ll only have to scan up and down on the meridian. In fact you can get the altitude of Venus using Stellarium making it even easier.
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