I use a variety of containers depending on the plane. Some contain only 4 or 5 screws/washers+spares. Others have nuts and bolts along with wing struts. For my B-25 I have nut, bolts, machine guns and a nose canopy.

The important thing is to get yourself in the habit of looking for that plane-specific box every time you get a plane ready. Then you onlt risk leaving the Tx home : )