Comment by ted

Based on seeing lots of beginners (me, too, at one time) do ground planes wrong, this video may help:

Hans Rosenburg explains some tricky concepts very clearly. The upshot is

a) 4 layer boards are much easier to get right

b) you really need an unbroken ground plane for return currents. This is often incompatible with having just two layers.

c) putting the ground plane much closer to the protected signals is a really good thing. Again, that means 4 layer boards.

Comment by ted_dunning