Okay I just came up with this idea tonight, and am wondering if it will work. So my idea is to us a Stereo cable to run from my pedalboard to the amp. I'm thinking that you could put a TRS Neutrik jack on the pedalboard and wire it for two separate cords to the pedals, and on the other end put two plugs for the amp effects send/return. Would this work? It'd be one less cable to run back and forth. What do you think?

So you mean converting the send and return jacks on the amp to a single stereo jack? That would work if the send and return jacks share a common ground connection and you had the proper switching going on with the new stereo jack.
no I mean that I would solder two seperate plugs for the send and return on the amp. But wouldn't they both share a ground already? When a cable connects the send/return they would have a common ground right?
Is this a serial or parallel effect loop? Either way there should already be two seperate jacks on the amp for send and return.

Or are you talking about adding an effect loop to an amp that doesn't have one? Sorry, I don't understand what you are trying to do here.
I just want to have one less cord running to my amp... I already have an effects loop on my amp. All I want to do is use one stereo cord instead of two mono cords. My plan is to just wire one end of a stereo cord with two mono plugs (one for send and one for return) and the other to a jack on my pedalboard
You would need a breakout box to direct the signal to each pedal but the theory is sound. The more expensive but extremely versatile option is something like the pedal snake wiring system which uses a multicore cable for send, return, power and anything else you want to use it for.

Or do it cheapo like I used to and wrap your 2 existing cable in wiring harness tape so they are bound together. Not as elegant as a single cable but effective.