Fear not! Free stuph is easy to find all around you, you just have to look on odd places.
Step 1: Where to Look
You already bought the parts once, why buy them again? If it doesn't work, cannibalize it!
2. Recycling drop off sites.
Sometimes, if you ask nicely, they might give you old donated items to tear apart.
It may cost a little money, but it is a repository for cheaper alternatives.
Remember, there are no guarantees that you will get what you need, but it is a place to start.
Step 2: What to Look For
I usually go for, in this order:
3. Buttons/ switches
7. Whatever else I can get my usually grubby hands on.
Your results may vary, satisfaction not guaranteed
I recently got a free computer tower. It is a treasure trove, but alas, I can only grab certain things.
Step 3: What to Get at It With
I usually have with me at all times when doing this:
1. Wire cutters
I detest cutting wires, it usually means splicing later on. But it is a necessary evil.
I love it. Continuity, voltage, resistance, yay.
For prying, poking, prodding, levering, and occasionally unscrewing.
4. Soldring iron & desolder bulb
I love to solder and to get at things involves meling some metal. Otherwise, parts don't come off boards.
For dinky screws, wires, parts, splinters...
If you don't know how to solder at this step, go learn. Seriously. I believe it is the single greatest skill to pick up.
Step 4: Digging In
For things stuck to the board:
Through hole - Press your iron to the leads on the bottom and try to push them through. Work one lead at a time and rock the component in the opposite direction. If it doesn't go al the way, stop and work on the other lead. Keep working, it will come off...or break.
SMT - suggestions? I'm a little inept at this and would gladly accept help.
Wires - They are generally either through a hole or in a clip. If through a hole, press and pull it out. If it is in a clip, look for a clasp that keeps it in. If there is one, unclip it; if not, try gently tugging.
If you have a driver, great! use it.
If not, try and improvise, like using a flat blade diagonal, or a phillips head may work. If push comes to shove, try driling it out or using a screw extractor.
I hate it. It breaks, it looks bad as an exterior, and has a myriad of little clippees formed into it that make disassembly a pain. Look carefully to find the clippees and gently unclip them.
Step 5: Physical Parts
Actually, Gutters and downspouts may make a neat case.
Frankly, anything that can hold your project could be a case.
I hate to say it, but even dumpster diving can uncover neat cases. Anytime something breaks, save it. It may make a neat enclosure. Tins, plastic tubing, other cases, anything.
Be thrifty! It's cheap!
I'm thinking of using an empty 2 pound goldfish box for something or other.
Caution. Some cases will not only be cheap, they will look it too. If it looks like you just slapped it together, it will earn no style points.