Upcycling Metal

Recommended books and other resources

A tetanus shot or booster if it's been a while since your last one. Find your medical records and talk to your doctor this is not a joke
The Illustrated Guide to Crafting with Tin, Wire and Foil by Simona Hill
Don't Throw It Out! by Lori Baird and the Editors of Yankee Magazine
How To Keep House While Drowning by K.C. Davis, L.P.C.

Spiffing it up

Sharpies will write on metal or glass and the color will stick around for years.

Chipped up messed up metal utensils

Great as trowels. In fact, I've used actual trowels that bent on me in heavy clay soil. Spoons and knives repurposed from the kitchen? Nope.

Danish Butter Cookie Tins

Store sewing supplies, seed packets, or buttons in these. If storing seeds, throw in some desiccant packets too, or maybe a bunch of chalk and baking soda. But label the tin if you want to prevent people from being disappointed. Or, use the containers to store other cookies, or crackers, or snacks. Or fill with various holiday foods and gift to somebody. Or family pictures. Come to think of it, these tins are so durable and handy that you can store any cool thing in them. Don't toss them. At the very least give yours to someone who treasures them.

Metal cans

Upcycled Tin Can Organizer at Mountain Modern Life
Tin Can Roses from CJStephens on Instructables
Hot glue fabric around them and on their bottoms to avoid rust stains on surfaces beneath, tucking the fabric over the raw edges and hot gluing on the inside seam also to prevent cuts from any stray metal bits. Use as catch-all containers. You can also paint these on all their exterior surfaces and let them dry, then duct tape over the inner seam.
Robot boy at Empress of Dirt

Old Metal Pots and Pans

DIYncrafts Pots and Pans Repurposing List
You can often still use these as double-boilers when preparing things like lotions, melted wax for candles, oils for soapmaking, DIY stuff with beeswax, furniture polishes, and so on. Since the liquid in the double part of the double boiler setup never contacts the simmering or super-warm water beneath, it doesn't matter if it's scratched up or rusty. I like to either use a clean metal bowl for the top bit or a glass pyrex measuring cup. Or, a mason jar on top of a metal vegetable steamer will also work. Bear in mind with any DIY double-boiler setup if anything is made of glass it could explode; if anything is flammable it could catch on fire, and everything I mention on this site could (despite being unlikely) in theory kill you.

Metal oatmeal or coffee canisters

Good as holders for kitchen stuff like spoons, spatulas etc.
Good as holders for art supplies such as paintbrushes
Decoupage right onto these with clipped out images, or with tissue paper as seen on Creative Jewish Mom

Metal folding chairs

Use as “the chair” for laundry in bedrooms. Perfect for stuff you have worn already but want to get a few more uses out of, and great if you do not want it to end up on the floor.
Store stuff in guest rooms on these
Not fancy as side tables but usable as side tables

Rectangular food tins

Drink cans

Heads up a lot of these projects are more involved.
Atomic Shrimp's Drink Can Tinwork
Check out Instructables for the solar powered drink can heaters. It's great for workshops, garages, and power outages, and you never know when you might need to have one around.

Aluminum foil

Wrap items in this to make better surfaces for burning candles, such as old cutting boards, pieces of cardboard, etc. Never burn candles unattended and keep a fire extinguisher and bucket of water nearby.
Sponge this off. Put some of this in a camping backpack and bend it into shape to help start campfires by keeping the fire out of the wind
Sponge this off and let it dry. Repurpose it into ornaments for a Yuletide tree, or for garlands of ornaments, either using your own creativity or with directions from The Illustrated Guide to Crafting with Tin, Wire and Foil by Simona Hill, which in my opinion is a seriously underrated book
Sponge this off. Tape it onto inner portions of windows as a poor man's air conditioning bill reduction treatment, leaving the lower half or some areas uncovered so you can still see through it if you are near it. Credit goes to someone on Instructables, I can't remember who exactly.

Metal Coat Hangers

Bottle Caps

Checkerboard with bottlecaps They can also be used as other game pieces and game tokens. If you'd rather they have some heft to them, you can fill them with melted wax or plain all purpose glue.
Can be added to any mosaic work for artistic effect if you really like bottle caps
Use as "currency" for any gambling game such as poker, Black Jack, or whatever

Filing Cabinets

From defunct link http://blog.tttreasure.com/2012/turning-your-old-file-cabinet-into-a-garage-storage-favorite/