I have about eight separate 16ga grounds, and I really don't want to attach each to ground, but instead to one single ground.

What is the best way to go about doing this? Originally, I had each splice in at a point on one main wire, and each was soldered on there (it looked like a tree). Evidently something was wrong with the way I did this, and I ran into problems. Is there a better way (ie junction block or something) to connect eight 16ga grounds to one? Is there a certain gauge I should be looking for on the single ground? I feel it should be at least 12ga, maybe 8ga?

Thanks!