Marco is one of those musicians that can make ANY synth sound good ("keyboardist not the keyboard"). One thing that us mere mortals should always do (if possible) is to play the synth in MONO mode (to avoid any possibility of accidentally playing more than one note at a time). Other tips; stay in the natural range of the instrument, don't use the extra dexterity of the keyboard to play faster or more complex than you could on the real instrument. If it's a wind instrument, allow for 'breathing' (a sax player can't play for a solid minute without taking a breath). In the absence of a breath controller, practice using velocity (touch) to emulate the dynamics of the real instrument. Play legato and use 'slurs' where appropriate. If all this fails to produce a satisfactory result, go down to the musicians union and hire a sax player .

chas