Thanks, hopefully daily practice will pay off in the near future. =)

I've found box modelling works best for me; Spline and Poly modelling meant filling in a lot of the space with my imagination until I got around to modelling it, which I hard a hard time doing effectively and so ended up messing my propotions up horribly ^^; (even when I used blueprints)

I only use blueprints when I'm trying to get the exact proportions of a form in, like a body, or the frame of a car. After that I rely on the concept sketch for finishing off the details.
Usually I do without them though, and just model straight from a concept sketch in my hand or on the screen somewhere, as is the case with all the models I posted above.