In terms of female muscle growth I usually like the idea of gradual growth and presenting it with a before and after with a cut to black between. This is beacuse I love the effect of seeing a sudden size increase as a surprise. However I am working on a couple or stories for which real-time growth would be better, to that end I've started experimenting with some new methods and tried it out on a character from an upcoming story. Here's a sample.
There is a longer version on the paid tier.