To be honest I can't really relate to this whole extra-help from professors/lecturers business. Nobody's going to magically make you understand something. Your best option is to come up with some specific questions which you figure are key to advancing your comprehension - but actually there's many places to go for those answers. If I was looking for feedback on a large (extra-curricular) project I would at least prototype it or draft it before asking for an appointment. I guess I'd just feel sort of embarrassed asking something to the effect of "i've got no idea where to start, I need your guidance." On the other hand, maybe that's been a hinderance to my (academic) career. Shrug.