Here is my very first PCB design. Two layers, one for signals and one for ground and power. No shared vias. All low-power capacitors located super close to their targets. The upper side of the bottom plane is for the analog ground, while the lower part is for the digital ground. Both are connected underneath the ADC controller, which should reduce the risk of ground loops. Very symmetrical design. And everything fits on 102 x 38 mm, which is quite a feat considering all the large electrolytic and tantalum capacitors that we had to fit in. And we have some extra room for future changes, like an 18 V to 15 V power regulator. Did I miss any best practices?