Is that good practice? I have a GND plane, but am wondering if I can make things that much ‘quieter’ if I put a ground pour around my resonator which is right near my MCU.
Thanks,
The resonator ground should be connected directly to the nearest MCU ground pin.
Generally, a continuous ground plane should be poured over the whole board, and any ground connections should be made with vias as close as possible to the component leads (for SMD components) or soldered directly to the ground plane (for through-hole parts - thermal reliefs should be used in this case to make soldering easier). I would do this in your case. There are some exceptions, but you have to be careful.
For example, some analog circuits may remove a section of ground plane around certain areas to reduce the capacitance seen on certain high impedance lines. In other cases, split ground planes are used in an attempt to remove digital noise from an analog section, but you need to be very careful with tracks that cross from one section to another, or ground loops will be introduced.