Sri Humananda
Advaita Vedanta Tantra Yogi
"The enquiry "Who am I?" is the principal means to the removal of all misery and the attainment of the supreme bliss. When in this manner the mind becomes quiescent in its own state, Self-experience arises of its own accord, without any hindrance."
(Sri Ramana Maharshi)
It is said by those who Know that when one looks for signs the act of looking actually gets in the way of seeing them. Signs are really nothing other than the conscious observance of a synchronicity between oneself and the world and time. When in tune with yourself everything becomes a sign and then, knowing this, signs become unimportant as such though they do not go unnoticed.
However, for us 'down here' signs we recognise tell us that we are in tune. That is if we observe a sign naturally rather than looking for one. If you are looking for signs you will find them all over. It can even become an instrument to look into those things one considers as signs and why, or 'make into' signs, and why.
But the good advice is to forget about signs in general as some higher revelation. You will be shown the signs you need and you will see them. In the end everything is a sign, or rather, significant. It's only a matter of degree as to our openness or closeness to ourselves that the usually non-obvious signs become conscious to us.
Related to this is the question of control - am I influenced by the sign or does it influence me? It is a worthy question because the matter of influence is what the Holy War for the Recognition and Maintenance of the Inside Consciousness is all about. Most do not recognize it or that it is a choice, and so don't see the War at all - only the bloodshed.