Basically you want one point of "ground". This is usually the point where the safety ground and the neutral are bonded together (by law usually), most often at the service entrance. THIS IS GROUND. make no additional to bond to the outside, from there you usually have your bonding to the ground stakes, but remember ground is at the bonding point, not outside the building at the stake, its really a reference point, not "ground". there is no such thing as ground. Building codes vary alot from area to area so your case will require local knowledge.
You can run home runs from that point to have clean grounds, such as isolated grounds, but that is your ground point. Putting in additional stakes into the earth can put your equipment at risk of damage during transient events (surges, lightning, etc)
Making sure all equipment connects well to ground is the important part. Having a clean path to ground is also a good idea. Additional stakes is not a good idea. You can upgrade your existing stakes to have a lower impedance to ground, thats not a bad idea, but they connect directly to the bonding point and no where else. The bonding point is ground.
The bonding point is ground. Want a star ground, go from there.
I think you get the idea.
if you want to look at lowering the impedance of the earth connection long term, there is a lot of newer research that has been done on concrete grounds, very interesting and stable over time.
Cheers
Alan
