Install jacks at the same height as electrical outlets. Wall-mount phone jacks should be 48 to 52 inches from the floor. Cover unused wallboxes with a blank wall plate to protect and mark their location. Stranded wire is used for extension cords, distribution cords, patch cords, and where data rates require it. Standard wiring is easier to troubleshoot and less likely to result in confusion later.
Every connection degrades system performance, so use the minimum necessary.
Better to provide excess capacity in terms of cable and outlets than not enough. Later additions are costly and time consuming. At the very best, the system will transmit signals to the level of its weakest component. Every element and connection is important. Document all connections carefully, and keep installations neat and tidy.