THIS! Even on my little 250, I only use the clutch for taking off, and 1-2 shifting. On that bike you need every little bit of technique possible! I downshift without the clutch when I'm slowing down, otherwise it's a quick partial pull of the clutch lever, and crank the throttle as I let out on the clutch. One important thing is to chop enough throttle to let the shifter completely cycle. I will occasionally get back into the throttle too fast and the shifter won't return to make the next shift. It might also be just my old foot moving too slow, but once back on the throttle, the load will not let the shifter reset like it should, resulting in missing the next shift. Some bikes "like" to shift without the clutch, others take a more precise technique to do so. The Interceptor 500 that I had would shift without the clutch easily, and the Ninja 250 took a bit more finesse. Probably the best technique to learn is the finesse of just barely pulling the lever, as you have a light pressure on the shifter. Light pull on the clutch while chopping the throttle (slightly, just enough to keep the RPM's from flaring) will let the shifter go on into the next gear. This will alleviate the damage you could be causing by shifting without the clutch, and minimize the wear on the clutch. It's all about knowing your bike, the clutch friction points (where it starts to grab, AND where it starts to release), how much pressure the shifter takes, and how much throttle to chop. Practice is the only answer!