Take nothing for granted as beautiful or ugly, but take every building to pieces, and challenge every feature. Learn to distinguish the curious from the beautiful. Get the habit of analysis - analysis will in time enable synthesis to become your habit of mind. 'Think simples' as my old master used to say - meaning to reduce the whole of its parts into the simplest terms, getting back to first principles.
Life is the only art that we are required to practise without preparation, and without being allowed the preliminary trials, the failures and botches, that are essential for the training of a mere beginner.