1.
If you say that someone dusts something off or dusts it down, you mean they are using an old idea or method, rather than trying something new.
Critics were busy dusting down the same superlatives they had applied to their first three films...
PHRASAL VERB: V P n (not pron)
2.
If you say that someone has dusted himself or herself off or dusted himself or herself down, you mean that they have managed to recover from a severe problem which has affected their life.
She dusted herself down and left to build her own career...
PHRASAL VERB: V pron-refl P