What does prioritizing mean?
MAs in particular are designed to help students reflect on the concept of relevance, that is to make them identify what is relevant for their studies and what is not. The same goes for PhD students at a higher level. This means not just prioritizing between areas of research and writing up, but also juggling between different commitments (e.g. job, home, research).
Being aware of the relevance of a source or of a piece of information therefore means being able
Once you have ascribed to each single task the right degree of relevance, it will not be difficult to differentiate them, that is, to distinguish the tasks that you should carry out (and the materials you should investigate further) from the ones that you can abandon. Or rather, that you must abandon. Matisse used to say 'All that is not useful in the picture is detrimental'. Your PhD thesis (and your research in general) is a picture, too. It must have a foreground and a background. If you want something to be immediately visible you have to bring it to the fore, otherwise it could pass unnoticed. If you come upon an issue worth examining in itself, but marginal as regards your research, put it aside or, simply, dump it; otherwise these marginal aspects will have the upper hand over the fundamental ones in the general picture of your thesis. It is therefore important that you distinguish between the strictly relevant aspects which should be retained and those generally interesting issues which should be reserved for another time.
This work of continuous evaluation, differentiation and selection will drive you to an effective prioritization of your commitments and, consequently, to the fruitful management of them. Working under the pressure of 'last minute panic' can sometimes turn out to be an effective trick, but the real trick is to avoid relevant tasks becoming urgent.
So don't forget to prioritize your research continuously according to the relevance of your different tasks and to be ready to re-evaluate all priorities. You will then end up with a helpful timetable which is quite fluid at the top and becomes firmer and firmer as you move downwards.