I'm trying to figure out best practices regarding ground layout, but it seems the more I read the less I understand about the subject as many recommendations seem to contradict themselves. So far I am under the impression that when using a ground plane one should route the specific node through a single via / contact directly to the ground plane. Others seem to recommend that stitching multiple vias to the plane works better since that decreases resistance. From what I've read the latter technique could be prone to introducing ground loops though, which I want to avoid. Right now I'm lost as to how I should layout the following PCB:
The first picture shows the top layer ground filled and both caps and casings directly connected to that fill.
The second picture shows the same layout as the first, but with an additional ground fill on the bottom and stitching vias connecting both ground layers. The return is for the 3.3V supply only, the two unmarked connectors in the middle transmit the balanced signal to a differential amplifier down the line. I am under the impression that the second way would be overkill for this example, but I'm trying to learn what would be the best practice here. Many thanks in advance!