The sign will make sense to maybe only you, and it will agree with you and the meaning you take from it. Our minds and senses are more powerful than we can comprehend. Each thought and feeling is unique to our reality of this life and Universe, as are the signs we receive, and so should we receive them. When we receive and believe in a positive light, we live in a positive light.
Signs can be from Mother Nature, or they can be manmade. If you perceive something as a sign for you, take it as one. If it speaks to you, it's meant for you.
Many times signs come through readings for me. They pertain to events in my life and sometimes answers that I seek. I feel blessed for these occurrences for the Universe keeps telling me I'm on the right path. The Universe knows all of our secrets and will engage with you if you desire, and you believe.
Positivity begets positivity.