Most harnesses will come with a minimum of four gear loops (two on each side) as that is a sufficient amount of space to efficiently rack gear for a climb. Generally, I like to split my rack (quickdraws, cams, nuts, etc.) between the front two gear loops on the right and left side. This allows me to quickly get to the protection with either hand while I'm actually climbing. Then I like to put other gear on my back two loops such as extra slings, anchor building material, belay devices, etc. Some harnesses can have more gear loops which allows for more detailed organization but I've found that for the majority of my climbing four gear loops is just fine.