Well, you can describe what the character is looking for or around where the character is searching.  Make mention of anything that has gained their particular interest.  If you want to make the roll, that is fine with me.  I use the rolls to guide what clues I give, the interactions that are going on and the scene to give it a flavor of spontaneous and also that the characters are affecting the world.  There are rolls being made without your knowledge.  Deliberately investigating though along with mention of clues, utilizing rescources and such does stack the odds in your favor.  So that is something to keep in mind.