Perseverance
Patience
Outstanding Focus
A Tripod
I left out the obvious 'good exposure' because even underexposed or overexposed images can, in certain circumstances, bring about a desired effect. So, having said this, it is important not to get too wrapped up in that super-auto camera, or than fast high dollar optic. Even being brand-specific is not necessary. Nearly any camera system available today can produce good images. Great images come from what is behind the camera.
Here is a partial list of the equipment I take with me into the field:
Olympus OM4T SLR
Olympus OM2S SLR
16mm f/3.5 full frame fisheye lens
20mm f/2 3.5:1 macro bellows lens
21mm f/3.5 super wide angle lens
24mm f/2.8 wide angle lens
40mm f/2 standard lens
50mm f3.5 1:2 standard macro lens
90mm f/2 1:2 macro lens
135mm f/4.5 bellows macro lens
200mm f/4 telephoto lens
300mm f/4.5 super telephoto lens
Telescopic macro auto extension tube (65-116mm)
Motor drive
Olympus T32 electronic flash
Cable release
Polarizing filters
Multiple focusing screens
Bogen 3021 tripod
Bogen 3265 Grip Action tripod head
Pentax focusing rail
Tamrac photo backpack
Spare batteries
Spare spare batteries
Sig Sauer P229 .40 caliber semiautomatic firearm