I have never struggled with writers block. Mostly because I believe that there is no such thing as a bad idea, but also because I believe in the power of lists. In one sense the creative process can be very mathematical, and yes mathematics can be very creative.
Sometimes I will force myself to come up with twenty occupations for a character, not stopping when I find one that I like. Often I will ask myself what occupation would this character never have? It’s amazing how many creative gems you can find through the power of the opposite.
Creativity is also different to maths in this sense… often it is better to be wrong than to be right; sometimes to be “great” we must be prepared to be very terrible.