When designing the PCB tracks keep in mind the following:
Keep all discontinuities as short as possible.
Use as many ground connections as possible within the allocated space or pinout.
Establish a common ground within the connector.
Use low-dielectric-constant board materials.
Maintain the ground path length as close as possible to the path between both signal and ground.
Route all traces orthogonal between layers (horizontal versus vertical layer).
Avoid vias between planes for all traces, clocks, and signals. All traces must be on the same plane, if possible.
Do not daisy-chain clock or high-speed traces. Use radial clock distribution. Terminate all signal and clock traces in their characteristic impedance. Make the terminating resistor the last item on the bus if end termination is used. Use the slowest logic possible. Design all traces as transmission lines.
Schematic design of PCB projects 
