Tips for not "missing things" in a dungeon

Hey all, my group is relatively new to DnD, we've all been playing for about a year now. We've just started our 2nd adventure, and the DM recently gave us some feedback that the party is consistently missing things in dungeons/quest areas (I assume "things" includes both items and alternate routes or secret passages).

When we enter a room, or search an area, we'll typically use phrases like:

• I scan the room for movement or suspicious items
• I search the floors and walls for traps/secret passages
• I inspect the crates/boxes for anything of value

This seems fairly specific to me, but clearly we are missing something. Are there any specific phrases/questions or actions we can take to make sure we don't miss stuff?

Note: one thing we haven't been doing is using the "detect magic" spell. is this something we should be using regularly? seems like a lot of spell slots could be wasted by casting detect magic in every room of a dungeon.