Phase start
Change the tone of your synth patches or samples by adjusting the start time (phase) of the oscillators or audio. With this technique you can get the sound more snappy (if at a peak, for example) or smooth (if at a zero crossing, for example).
This particularly works well to get tight bass lines or when you want to align percussion.
By contrast, on some instruments you can also randomise start time with modulation to get different accents: this is particularly useful to make drum samples such as hi hats, to sound more humanised.