You have been warned.
One of the first rules of doing illustrations is you charge for what you do. The second rule of doing illustrations is to sometimes ignore the first rule.
I have asked several professionals about pro bono work and every time I was told that you have to charge at least something. Even if its just twenty quid it from your mate who needs a cover for his band's EP but is stuck for cash who says he can recommend you for all kinds of paid work once they get picked up and you will absolutely be brought along for the gravy train ride into roast turkey station. But most likely you will be the peas or sprouts, acknowledged for your contribution to the overall aesthetic of the meal but discreetly brushed aside and hidden under a napkin. Tomorrow is pizza night anyway.
This is a worst dinner scenario, but not an uncommon proposal if your starting point is 'which of your friends or family could pay me for something'. My advice would be not to get overly invested in agreements like this as, in my experience, it rarely plays out successfully. It is of course good practice at the start to do a few of these jobs, if for no other reason than getting some idea for possible avenues of work as well as gauging how fast you need to work on a deadline. Just be prepared for your would-be client to come back with a few suggestions for re-do's and little appreciation for the hours it's taking out of your other stuff cause screw it your doing it for free and there in no momentary investment in it. Here's an example of what I mean which happens to be hilarious; 27bslash6.com. If you charge someone twenty or thirty quid for it and they come back and say they want it "different but the same", it's much easier to turn around and say "okay, that'll be €15 for me to do alterations". This creates the possibility for some extra cash while simultaneously restricting how much work you'll have to do for them.
The most free work I've done is for my older Brother. He has run a number of really good comedy shows around Dublin and has sold out shows in the Edinburgh Comedy Festival. And the Fringe Festival if that isn't the same thing. if it is, he did twice as good then. Part of my style has become part of the branding for the shows. My love of black and white (with maybe one colour) suited the aesthetic he was going for.
The first show was called 'Eat Cake' after that very famous French lady who didn't understand how the whole cake/bread to rich/poor thing worked.
The first image was a guillotine that had cut off a slice of cake. There was no research done as an image of a guillotine had been branded onto my brain by a particularly grim episode of Tom and Jerry earlier in my childhood.
Another show is called 'Auntie's Establishment', which I thought was a great name for a fringe comedy show.
Critical thinking. It's where it's at.