My current one took 5 minutes in Photoshop. As you can see. I had a better one but I felt this one is more entertaining. I don't really do sigs any more but I've got some oldies. This is my most recent proper one:

Which copied the render from:

One of my better first (probably the 3rd sig I'd ever made) ones:

The thing is though, "proper" sigs are boring because most people just brush the fuck out of it, apply various filters and colour layers, then add the render. Generic sig formula right there. That's why I stopped doing them. When I do use photoshop it's for either Graphics or Media Studies these days, and I'm working on learning texturing so I can do some skins for Carball. But I doubt I'll do many sigs in the future, unless it's for parody purposes.