A method of optimizing a premix fuel nozzle for a gas turbine, the premix fuel nozzle (12, 22) comprising a burner tube having an internal wall, an open internal volume having a length extending between an upstream end and a downstream end of the burner tube, a longitudinal axis, and a cross-sectional area perpendicular to the longitudinal axis, the method comprising the steps of: (a) fabricating a nozzle tip, comprising the steps of (i) fabricating an outer body having an outer body external face facing the downstream end of the burner tube, said outer body external face having a smaller cross-sectional area than the cross-sectional area of the burner tube; and (ii) fabricating one or more segments radiating radially outwardly toward the internal wall of the burner tube from said outer body, said segment having a set of physical dimensions, said physical dimensions comprising a height, a width, a shape and an inclination relative to the longitudinal axis of the burner tube, each one of said set of physical dimensions selected to provide a desired nozzle flame shape; and (iii) fabricating the nozzle tip comprising fabricating an inner plenum; and (b) installing the nozzle tip at least partially in the burner tube, wherein the step of fabricating the outer body comprises making the outer body to surround the inner plenum; and fabricating an open end, a closed end and the outer body external face on the closed end facing the downstream end of the burner tube; characterized in that the step of fabricating one or more segments comprises fabricating at least one segment having an internal conduit having an open proximal end in fluid communication with the inner plenum; in operation, air is adapted to pass from the inner plenum into the internal conduit; and the step of fabricating the closed end comprises fabricating an internal face adjacent to the inner plenum, and a plurality of bore holes extending between the internal face and the outer body external face in the closed end. (a) fabricating a nozzle tip, comprising the steps of (i) fabricating an outer body having an outer body external face facing the downstream end of the burner tube, said outer body external face having a smaller cross-sectional area than the cross-sectional area of the burner tube; and (ii) fabricating one or more segments radiating radially outwardly toward the internal wall of the burner tube from said outer body, said segment having a set of physical dimensions, said physical dimensions comprising a height, a width, a shape and an inclination relative to the longitudinal axis of the burner tube, each one of said set of physical dimensions selected to provide a desired nozzle flame shape; and (iii) fabricating the nozzle tip comprising fabricating an inner plenum; and (i) fabricating an outer body having an outer body external face facing the downstream end of the burner tube, said outer body external face having a smaller cross-sectional area than the cross-sectional area of the burner tube; and (ii) fabricating one or more segments radiating radially outwardly toward the internal wall of the burner tube from said outer body, said segment having a set of physical dimensions, said physical dimensions comprising a height, a width, a shape and an inclination relative to the longitudinal axis of the burner tube, each one of said set of physical dimensions selected to provide a desired nozzle flame shape; and (iii) fabricating the nozzle tip comprising fabricating an inner plenum; and (b) installing the nozzle tip at least partially in the burner tube, wherein the step of fabricating the outer body comprises making the outer body to surround the inner plenum; and fabricating an open end, a closed end and the outer body external face on the closed end facing the downstream end of the burner tube; characterized in that the step of fabricating one or more segments comprises fabricating at least one segment having an internal conduit having an open proximal end in fluid communication with the inner plenum; in operation, air is adapted to pass from the inner plenum into the internal conduit; and the step of fabricating the closed end comprises fabricating an internal face adjacent to the inner plenum, and a plurality of bore holes extending between the internal face and the outer body external face in the closed end.