was in the same posn.
didnt use any "structure" as such. But tried to put a positive spin on things . For example instead of telling them first abt why my current supervisor is not recommending me..........I told them why my earlier boss was more qualified to provide me with a reco.
Similarly in the grades explanantion......I concentrated more on telling them what happened cause of me flunking one paper (as in how I learnt my lesson an never smoked weed before a final exam again
as opposed to telling them why I failed that paper in the first place (generally this is too whiny)