shifting takes practice. find a big parking lot of a sunday morning and ride until your clutch hand looks like michael j fox's.
for upshifts, preload with the foot underneath the lever, then do a partial clutch pull and nudge it up. helps to have the revs up before shifting. if i'm short-shifting, i'll give the throttle a tiny-ass blip while i bump the lever up to juice the engine speed.
for downshifts, read up on rev matching. basically, pull the clutch and at the SAME time blip the throttle and kick down to the lower gear. you can let the clutch right out and, if done properly, engine speed should match rear wheel speed when the clutch engages and it'll be a really smooth transition (no whine).
i'd say it took me about 800ish miles on the '08 shiver (750cc) before i got decent at shifting smoothly. that was a terrible choice for a first bike, but the price was insanely low due to the exterior abuse, the weight/balance seemed great when i sat it, and i wanted an unusual (or so it seemed to me) bike. DERP. boy, the salesturd told me EVERYTHING i wanted to hear to get it off the lot: "ah, the power's totally manageable!" "i'd ride this as a first bike, no problem." "you'll appreciate the big first gears starting out, you won't hafta shift above second in town! it's almost like a scooter" AHHH HURRRR. once i got 2.5K miles on it and felt i could ride about anything with a vague sort of confidence, it done got traded for a gladius. that was a MUCH better starter, and i love it so much i don't plan to sell it. i could hoon on that little bike all fuckin' day (and somedays i do, when i COULD be trolling gaf nintendiddlers).