I'm not a graphic designer, so I generally try not to do things that focus on the design -- which means I tend to start on the whiteboard/sharpie/napkin side of things.
That said, some people just can't picture how things look unless you show them how it looks, and in the past I've worked with clients that would think it's literally a joke (and probably fire me when they found out it wasn't) if I come to them with a sharpie drawing.
I think the only times I've gone to a more high-fidelity version up front is when the client/stakeholders had no idea what they really wanted. A "finalized" mockup can start the discussion (even if it turns out to be entirely wrong) and then be used to get into the low-fidelity whiteboard/sharpie mockups. The important thing is to keep the discussion focused on the right thing, and don't stray into fonts/images/icons if you want to talk about the overall structure and what pages even should exist.
That said, some people just can't picture how things look unless you show them how it looks, and in the past I've worked with clients that would think it's literally a joke (and probably fire me when they found out it wasn't) if I come to them with a sharpie drawing.
I think the only times I've gone to a more high-fidelity version up front is when the client/stakeholders had no idea what they really wanted. A "finalized" mockup can start the discussion (even if it turns out to be entirely wrong) and then be used to get into the low-fidelity whiteboard/sharpie mockups. The important thing is to keep the discussion focused on the right thing, and don't stray into fonts/images/icons if you want to talk about the overall structure and what pages even should exist.