Salamun Alaikum.
I make use of three guiding principles:
- Any serious attempt at Quranic 'Tafsir' or interpretation should be performed primarily in light of the Quran itself.
- Unqualified verses or narratives must be understood in the context and light of qualified verses or narratives. (Implicit verses must be understood in light of explicit verses)
- Lack of 'perceived' details of an event does not require one to source other material with a view to arbitrarily 'fill them in'. Many verses have subtle nuances and are complete in that they make clear the general purport of the message and wisdom they intend to impart. Intricate details are not of its concern. God does not run out of words (31:27).
I have parted with some general advice here for those that are primarily reliant on translations to access the Quran's message.
HOW TO STUDY THE QURAN - SUGGESTIONShttp://quransmessage.com/articles/how%20to%20study%20the%20quran%20FM3.htm
I hope that helps, God willing.
Joseph.