Porfolio question

Hey everyone.. I just have a question.. what do you (Pro's) look for when checking out portfolio's that people asking for an apprenticship bring it? I believe I have a strong portfolio (also have an excellent apprenticeship position) and I am still building it on a daily basis.. with new drawlings, sketches, and full paintings.. Im just curious as to what sticks out to your guys the most.. is it paintings? ink drawlings, lead drawlings, sketches, ect. or is it the presentation of the work in a whole.. I am a strong believer that a persons portfolio is pretty much like a resume in this buisness and should have much consideration when being put together.. I haven't seen this topic talked about on here. and since there seem to be ALOT of people that are working hard towards landing an apprenticeship postion I just thought maybe it would be an intresting topic to see what you guys had to say..