The first question you need answered is: How do you want your airplane equipped? I figured out that answer and bought it all with the help of the avionics supplier. I did that sometime after I started first working on the airframe and flight controls. When it came time to cover with fabric I thought of where all the stuff I had bought needed to be mounted. Its just minimal number of items like the ELT, com, transponder antenna, horizontal stab trim motor. Placement of these items had little to do with efficient routing of the wires but more to do with, the KF available space. I don't know how the next guys ELT is mounted but I figured out my own way and installed it. People here helped me get my antenna placement done. Wire route was an after thought. My wire harnesses reveal this Im afraid. I wish it were more professional appearing but hey, I have never done this before and my stuff works. There certainly may be a day when you will come into something you were unaware of and have to figure that out too. Mine was the power boost safety trim item that is needed to allow the Garmin G3X to adjust the trim for the Auto Pilot servos when using the AP. Since I knew from the start I wanted an AP, I installed my servos as well. Those servos have no published method for installing so that is where this forum comes in. Plenty of pictures were provided to assist me in getting mine installed. The forum will be your savior more than once or twice.