Personally I find 5,500 RPM is a nice place to shift if you want to go quickly and not blow shit up. Also, check your oil make sure it is at the top mark on the dipstick. Check your oil about 15 minutes after you shut the car off if you just drove it to ensure most of the oil is back in the pan.
Rev to 5,500, mash the clutch, push it out of gear towards the next, once you feel it pop into the next gear drop the clutch and roll back onto the throttle. Rinse, Repeat.
if you want to shift even faster, rebuild your trans, get some of that sick purple shit to put in it and install a short shifter.
Then it's just practice, relearning your trans.