Overclocking beginners can boost performance by using the preset profiles, tuning sliders, or the OC Scanner.
The Voltage-Frequency Tuner is the tool of choice for overclocking veterans, and this tutorial goes through a regular use case.
Using slowly ramping curves as examples, this video shows the main fan tuning functions in GPU Tweak III.
The Profile Connect function lets GPU Tweak III auto-swap profiles, and this video shows how to set it up.