They watch the insects and the birds to see what they are up to and why. Most of all they know fish. They know all the different species and what their presence or absence means on a given day. They select their target carefully and they know exactly what they are doing every moment. This is a far cry from simply throwing a line in the water and trusting to luck.
Good fishers are also persistent.
They keep at it and at it until they succeed. In fact, nothing motivates a good fisher more than a difficult or elusive target or even worse an initial delay or failure. That is exactly what gets their competitive juices flowing. Good fishers are concerned about their total environment. You might say that they are really into Resource Sharing.