Back in the day I used a vector program called ArtWorks, which was the advanced vector package for RISC OS. However, it only had simple linear fills and no transparency, so for more complex images blends and colour mixing where the only way to get results.
Over the years both the software and I have improved a bit - I now use Xara Designer Pro, which is the offspring of ArtWorks but with a decade or three of upgrades.
Here's three faces to show how things have changed over the years. The first is from a photograph of a friend (hence the bright highlights from the flash); the second is an attempt at a more subtle style, but still restricted to the same limited tools; and the final image is a more modern one with better control over blends, fills and transparencies (as well as a tablet to draw some of the hair freehand).
Harrison Ford, 1993
I wanted to push myself to learn this new vector package back in 1993, so I chose this image of Harrison Ford from Blade Runner, with multiple complex light sources.
This was based on the covers of some hard boiled detective novels I found in a second hand book store.
This was a "failed" audition for some educational work - I was supposed to draw some anthropomorphic fireworks in a flat style, but even with the client sitting next to me I couldn't help but add some gradient fills to give them some depth. I think I actually went back after he'd left and added more so I felt happier with them!
I might have got the job anyway, but by the time the company came back to me to talk about it I'd already taken the job with ArgoNet.