Our design team needed our own set of icons to fit our needs, specifically — insurance software. We'd been using Icomoon's free icon fonts, but our specific use case — insurance software — meant there were several icons we needed that weren't included in the free set. Additionally, we required filled and outlined versions of many icons to allow for interaction in our products.
I determined which icons we used most frequently, and researched which icons were standard in most icon sets. I designed on a 64-pixel base.
Custom icons decreased the need to design new icons by accounting for our products' specific needs.
I've also documented these icons on Behance.