Based on my experience what worked for me has been:
1. Put audiophile grade network switch in front of your streamer - I use LHY8
2. Put the best network cable between the audiophile switch and streamer - I use Revelation Audio Labs cable. totally awesome cable, imo
3. Use very good power cords for both the streamer / switch and feed good electricity
4. use non-audiophile grade switches to avoid using a long ethernet cables. by doing this, it lowers noise I found.
5. If you had something like Synergistic Research Pod, put it on top of non-audiophile switch. It smooths the sound. I use one and it has made definitive improvement