I phrase it as "Standing problems I solve for free, sitting problems are my usual hourly rate." Which is to say, if I can solve your problem for you before I g

I phrase it as "Standing problems I solve for free, sitting problems are my usual hourly rate." Which is to say, if I can solve your problem for you before I get tired of standing up, I'm not going to bother to charge you. In my case that's usually a half hour or so. People seem to respond well to that, in general. I think it's in line with how most people view the value of their own time. It's also a one off, as well. Just because it only takes me 15 minutes a week doesn't mean it's free.