^^^ This. Learn your car/engine. Get to know how much power/torque the engine makes for a given amount of throttle, it will accelerate until it it runs out of power, or rather the acceleration will slow. I find it best to change gear just before this drop off occurs.
Conversely, when having fun I might rev out first a bit and then short shift straight to 3rd or 4th.
I just did a diff gear change on the missus car which is auto, I'm working on all the shift points based on how it now accelerates from the greater mechanical advantage of the 3.73 gears.