Regular cleaning of your guitar is very important. After playing, wipe down your instrument to remove any sweat. Sweat contains acids that can eat through the finish of the guitar, corrode strings and cause metal parts to rust. Gloss finish guitars should be polished with polish formulated specifically for musical instruments, and a soft, treated guitar cloth or a cotton rag. Abrasive rags such a polyester can scratch the finish. Oil finished guitars should be wiped down as soon as you're finished playing, with a dry cotton (baby diaper) rag. Don't rub real hard though. Remember cotton is a wood fiber and can scratch a guitar. You can also clean with a good grade rayon cloth. It cleans metal parts and pickguards without scratching them. Any fabric store should carry this. Never use paper towels.
Believe it or not, a good car polish can be used and can be bought at any department store.
If you're not sure about a polish always test it first in an inconspicuous spot before applying it to the finish of your guitar. Be very careful with the finish of your guitar.
Be very careful using Lemon Oil. Always apply it to the cloth first then to the fretboard. It just takes a little. I do mean a very little. You can ruin a good fretboard if it really doesn't need it.
You only need to do this every couple years. Some fretboards may not need this at all.
The best way to remove light scratches and haze from a nitro celluloid pickguard is buffing it. I've heard of people using toothpaste to buff out light scratches, although I've never tried this, it supposedly works.You can also water sand with micro mesh sand papers 600 to 2500 grit, then buff it up to a shine. When you polish and clean the pickguard, don't rub it with a cotton cloth or it will scratch again! Use a rayon cloth to clean plated parts and pickguard for non scratching since there is no wood pulp fiber in the synthetic cloth.
Gold Plated Scratches:
Don't even mess around with gold plated hardware. You'll do more damage than good. Just wipe the sweat off after use with a good rayon cloth. Whatever you do, don't use metal cleaner or steel wool on it . Some metal cleaners will take the gold right off and steel wool, hmmm, been there... done that...
Chrome Plated Scratches:
There's not much you can do about that. Just keep it wiped down and shiny.
Sometimes a little #000 steel wool can get the rust off if needed.
If you have minor scratches you can rub these out by hand.
I use a good car polish for this. Meguiar's Deep Crystal System step 2 Polish.
Buy it at any department store or auto store. Directions are on the back of bottle.
As far as waxing a guitar, any guitar wax is good. Remember it's always good to apply the solution to the cloth first then to the guitar.
If you're not sure about a certain wax for your particular finish it's always good to apply it to a hidden area first for testing. Be careful.
Fretboard Cleaning:I use a stiff toothbrush to clean the crud off the fretboard and then spray a little Windex without ammonia on a cloth (baby diaper) and rub down the fret board.
Just don't get carried away and soak the wood with Windex. It just takes a little. It works great and I have been doing this for over 15 years with no side effects.
If you need to use Lemon Oil, use it very sparingly.
If the fretboard is showing a little white-ish coloring in the fine cracks, then it may need a little. Be very careful using Lemon Oil. Always apply it to the cloth first then to the fretboard. It just takes a little. I do mean a very little. You can ruin a good fretboard if it really doesn't need it.