For many, many years I was using 10 mils / 10 mils (track/clearance).
Then I changed it to 10/8 (but allowing myself for 8 mils tracks if needed). But for zone fills I still used 10 mils clearance.
When moved to KiCad I changed from (standard in PCB technology) mils to mm.
Now 10/8 → 0.25/0.2 (but allowing myself for 0.2 mm tracks if needed). And, not surprising, zone clearance 0.25 mm.
My 2 layer PCBs are designed that way, that whole bottom side is GND zone. So I don’t have other vias then GND. I use as typical via hole 0.5mm as I treat it as power connection and not signal. For power pads (under ICs) i use via hole 0.3mm. For via stitching of big GND islands at top with GND at bottom I use via hole 0.7mm, but I consider to replace it with 0.5mm in future.
For VCC tracks I mainly use 1mm track, but sometimes up to 2mm.
An example of such designed PCB you can see here:
Hand-soldering SMD is even simpler than soldering THT. You need not to revert PCB all the time. 0603 is easy to solder provided you have right soldering iron.