Kevin you may not realize the complexity of your question; here's the basics. Most listeners feel that cable swapping at the source component is a good place to start; this is probably mostly true. No the cable pairs do not necessarily need to be the same. Sometimes that yields best results, sometimes a mixture works better. Experimentation is always required. Use the same source music material repeatedly for your auditioning; something you're very familiar with & of high quality too.
Cables are such a controversial area; everyone has opinions & different experiences. They are highly dependent upon synergy with your specific componentry; a cable that sounds great in one system won't necessarily be so in a different rig. Guarantee they won't sound the same.
Typically they need to settle in for awhile after installation. The time required can vary considerably; a few days to several weeks or more. Signal passing through the cable full time accelerates the process. Ensure the connectors are clean before you plug in; there are lots of contact cleaners available. At least use a Q-tip & 90% isopropyl alcohol if you don't have anything else. Don't use that 70% rubbing alcohol which contains water & oils.
Sometimes you'll actually determine more about the sonic signature when you remove a cable in place of another. You'll then realize what was missing or added.
Invest some time in the forum archives to further educate yourself in that regard. There's a lot of valuable info here, but you have to be willing to seek it out. As in all things, the amount of effort you put into the process typically determines the quality of your results. Best of luck & have fun.
