WOW..what a lot of good ideas...you are all sooooo inspirational....
For my bead trays I use the little soft platic lids that come off the top of yogurt pots and for larger ones I use the lids off oatmeal tubs. They are great because they bend in half for you to pour beads back in the tubes and go right back to their original shape.
My beading mat is the liner you use for drawers and shelves...(don't know what it's name is) but it comes on a roll and is about 18" wide and beads don't roll away on it and you can hand rinse it. Plenty on a roll to last for years to come.
As for my needle holder, is is a couple of corks from wine bottles I got at my son's wedding and I glued a couple of sheet magnets to the underside edge of my bead shelf to hold large head pins and bead stoppers. (The magnets are the 'free' ones that people use to advertise themselves and they are about the size of a credit card).
Finally, I shop my dollar stores for bead storage tubs as they sell the multi stacking tubs that have nails,screw etc. in them and are in clear plastic. (Usually 3 large round tubs or 4 smaller round tubes for $1).