So, priestly fraternity is a way of being rather than a duty to observe, because the priesthood is rooted in Christ.
The human dimension of priestly fraternity - again, something that is learned - is that a priest must first relinquish his own independence, and accept that his brother priests can help him to be open to what Christ wants of him. This is the first step to building priestly fraternity for it enables the individual priest to invest himself in fraternity and be open to receive from his brother priests. The Holy Spirit is undoubtedly at work when this happens.
The ecclesial dimension of priestly fraternity is also very rich. All priests share in the same mission - building up the Church. This involves an attachment to both the Holy Father and the Bishops, but what is really at stake here is a missionary dynamic. In other words, genuine priestly fraternity enables priests to remain focussed on their mission, which is the sanctification of souls, and to avoid becoming over-involved with activities which are not essential.
Another example of priestly fraternity, which was tremendoulsy enriching of my own experience, took place when I was a parish priest in Huddersfield. In 2007 I engaged the parish in a Parish Mission. The Mission was based on a series of waves of house-visiting throughout the Spring. The culmination of the Mission was the visiting of houses by priests. I had sent out requests to other priests to come and help me in my endeavour. Five priests responded and joined me in my parish. So, for a two-week period homes in the parish were visited by priests - and we went out visiting in twos! I was able to accomodate them all in the presbytery and to cook two meals a day for us all. We went out visiting in the afternoons and the evenings. Our priestly endeavour in the parish fed our fraternity and our fraternity fed our priestly identity. It was an extraordinary two weeks which I see, in some way, as a model of diocesan priestly life.