Scoping custom illustration in brand projects

I’m a full-time illustrator who gets pulled into brand identity builds, and I’m reworking how I scope custom visuals. For a recent startup kit, they wanted three hero spots and 12 icons, sketched in Procreate and finalized as vectors in Illustrator, with two rounds included. How are you packaging and pricing this — do you cap revisions, charge per piece or complexity, and where do you draw the line between the design system and bespoke art?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍‌⁠‌‍‌​‌‍‍‍​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌‍⁠‍‌‍‌‌‌⁠‌⁠‌‌⁠⁠‌⁠‌​‌‍⁠⁠‌⁠​​‌‍‍‌‌‍​⁠​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​‍​‍‌‍⁠‍‌‍‌‌‌⁠‌⁠​‍​‍​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‌​⁠​‌​⁠​‌​⁠​‌​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌⁠‍​‌​⁠‍‌‌‍‍‌‍‌‍​⁠‌‌‌⁠‌⁠‌‍‍​​⁠‌​‌​​‌‌‌‍‍‌‍​‍‌‌‌‍‌⁠​‌‌​‌⁠‌​‍‍‌‌​‍​‍​‍‌⁠⁠‌​