Keep some pressure on the shift lever as you let the clutch out. It may snick in to gear as you are doing so. With the 650, my shift routine is the following...
Slight pressure on gear shift...throttle down while pulling clutch and applying firm pressure to shift lever......after I feel the click of the gear lever....I keep up pressure and let the clutch out....THEN let off of the gear shift.
This cured any of my infrequent missed shifts. I saw this technique on either an AMA or MotoGP race when they had a neat camera angle down at the guys left foot.