I can give you an add to this:
Start off with a basic hair rig and adapt and play with it.
I mention the perfect hooking point, middle of the bottom lip. If you are losing fish to hook hookpulls during the fight at the start, are hooking them at the very front of the mouth, the hair is not long enough.
When the basic hair rig stops catching move onto the next development, the sliding or extending hair, or add a line aligner.
As @yonny says, a bottom bait rig, and a pop-up rig it really is that simple.
I don't fish zigs, so I can't comment on their effectiveness.
How effective your rig is can be changed by what and how you feed.
A rig with a short hair can be good for fishing over particles or groundbait, yet over boilies may be very ineffective. A rig with a long hair may be great for boilies, yet awful for fishing over particles; the long haired bait may be blown in and out with no hooking, or alternatively cause bite-offs.