In addition to Hobby Lobby here are some stores you might want to check out for tools and accessories.
Sallys- sanding-finishing tools
Harbour Freight- dental type tools,metal files, motor tools, mini clamps, opti-visors-magnifiers
Dollar type stores- plastic containers, toys and gift type items that have useful lights and fiber optics when you crack them open.
And of course Walmart, Lowes, Home Depot- rattle cans, bulk solvents (paint thinner, acetone)
You will get to the point where you think about things you throw in the trash or walk in a store and look at things and think "that might be something useful"
Example- my kids eat lots of pudding/jello/fruits that come in little plastic cups. Great for mixing paints, cleaning, storing parts, etc.