Making noise, or "creating a sound that isn't there in there in the first place", to quote one the best advices I heard in an interview (Agonal Lust's interview on White Centipede Noise), should of course be the primary question, along the lines of "What's the aim? What am I trying to create, transmit, demonstrate?" and so on.
In my opinion, a full-lenght release should never be a chaotic mess of sounds and images thrown in the same place for the sake of getting a lenghty amount of material that could somehow be considered as an album. There should always be an overall vision, so to speak, a strong motivation behind the material, which would then be transmitted to a label. Sometimes the material speak for itself, of course - imagery, sound, lyrics, titles, and so on - but how many times is it the case? Established names will certainly encounter less problems for that, but when it comes to new acts, I do believe that intentions should matter as much as the quality of the material submitted. Just like many others, I myself have often thought about submitting my demo material to huge labels like Freak Animal or Tesco and hoping to be taken in, but that would feel limited to a certain sake of visibility, and visibility isn't all. The material should first of all fit the likes of this or that label in the first place. If it doesn't, why even bothering yourself and the label owner by sending a recording? This said, it takes a lot of self-criticism, which often ends in so much self-criticism that nothing happens at all, and the material is discarded. Personal experience.
This said, I do also think that the best moment to approach would be in the final stages of an overall artistic recording - visuals, sounds, lyrics eventually - everything that could make the material's receiver decision easier, and even if the answer was no, would eventually allow the receiver to give some tips and suggestions - what should be done better, what was good, what was not, and so on. In the early stages of my project, when i first submitted my material, I received no answer from one label, and two good critics and suggestions from two others, which ended in an amazing collaboration with one and various qualitative exchanges with the other.