Sometimes (not always) I like to create "formulaic" waveforms based on some specific equation or principle. For example, a wave shape based on the Fibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13, ..). Or even just a modulated sine wave, where I know the formula better than I can draw the waveform by hand.
A better example might be creating a function Z = f(X, Y) where X is the position along the wave 1 to 2048) and Y is the waveform in the table (1 to 256), and Z is the amplitude value of that point in the table. I would like to experiment with different functions to see if I can find any that produce a cool sounding wavetable.
This is purely for fun — it may all sound horrible!