Whether to use a blend mode other than Normal depends on what you're trying to accomplish.
The 'contrast enhancing' modes of Overlay/Soft Light/Hard Light can increase contrast even without any Curve changes, or reduce it by inverting the curve. That can additionally be tweaked by actually modifying the curves.
Screen and Multiply are useful for lightening or darkening an image overall, as well as enhancing curves manipulation which tweaks those aspects.
It Depends 