Vogue Knitting has modular patterns for combining various design elements.
Also, Knitting the Perfect Fit has design instructions, too.
Knitting the Perfect Fit: Essential Fully Fashioned Shaping Techniques for Designer Results https://www.amazon.com/dp/0307586642/ref=cm_sw_r_cp_api_i_BESRQJBNCGPJ6MFT61T8