Via Stitching on 2 Layer PCB when top layer is not fully ground pour
On a two layer board, via stitching is probably not that helpful. The two most important things to reduce EMI:


make sure the ground plane is continuous below the power traces, so the return path is as close to the power trace as it can be. On a two layer board, this means that crossing power connections will be difficult and should be avoided if possible. Probably one of the least bad, but still bad ways:





filter the power supply near the ICs so high-frequency components don't reach the longer traces (i.e. decoupling caps, and possibly some inductors as well)