Tips & Tricks for a Professional Install
Use a high-quality Soldering Iron
Use a quality soldering iron, at least 40 watts and 750°F. This can make a huge difference between a clean install and an ugly install. Not having enough heat can burn components and make poor connections.(Beware of the Blob!)
Use a high-quality Solder
Culbertone harnesses are assembled with 60%/40% - Tin/Lead Solder (chemical symbols - Sn/Pb) that uses a 2% rosin flux core. Quality solder of this composition is commonly available online, if not sold over-the-counter in your state.
**DO NOT** use or mix Lead-free or Silver-based solder with Leaded solder, as it can cause "cold" or faulty solder joints.
Clean the tip EVERY time!
Clean your soldering iron tip between every joint. Use a wet sponge or a brass wool pad. Gently wipe the tip of the iron - removing oxidation, excess solder and rosin/flux debris.
Click the "Undo Button"
Solder is an amazing tool. But sometimes you over-use it, placing too much solder on your target joint. Furthermore, you might have connected the wrong wire to the wrong lug. Always have a mechanical or manual solder-sucker, and some solder wick on-hand in case you need to "undo" your connection. Note, these tools are essential in removing components from old connections (like when you are about to install a NEW harness).
Watchout for "The Blob"
Only use as much heat, and as much solder as necessary. "Blobs" of solder are not effective, and can cause "cold" solder joints (i.e. they will fail).
Jack be Nimble, Jack be Quick
This goes back to having a hot, quality soldering iron. Get in, get out. The longer your iron is in contact with the component, the more at risk that component is for damage, including changing its value, or shorting it altogether.
Love thy Multimeter
If you don't have one already, please buy an inexpensive Multimeter with: Voltage, Current, Resistance, Continuity, Capacitance, and Diode testing parameters. This is a great tool and an excellent skill to master if you plan to be working on the electronics in your guitars and basses. Rest assured, every component that goes into a Culbertone harness is tested for tolerances and function BEFORE final assembly. However, it is always smart to test the continuity of your connections after you have made them. Multimeters can be a lifesaver when troubleshooting connection issues.
Toothbrush, it's not just for Teeth.
An inexpensive toothbrush can be a valuable soldering tool for cleaning up the joint, especially if some of the rosin flux is still leftover, or visible on the joint. Always take a little extra time to clean the joint and surrounding area to remove loose solder blobs and rosin flux blobs that may have splattered around the joint.
Shields Up!
A cheap and effective RFI/EMI barrier such as Copper foil tape can be a game-changer for managing noise in your guitar's electrical system. Lining the control cavity, pickup cavities and the backside of pickguards can create a really effective way to keep noise at a minimum, especially if you play in a band live, where lots of unwanted stray signals can find their way into your sound.