I need help from someone who's experienced in editing photos with Windows Photo Gallery using Contrast, Color Temperature, Saturation and Sharpen. I don't know if a picture looks better if I were to decrease, increase or leave as is using those editing tools. I have absolutely no idea on what type of photos I should increase or decrease using Contrast, Color Temperature, Saturation and Sharpen and by how much or percentage wise? And should I even use Sharpen to edit my images?

I never decrease Color Temp or Saturation as it makes my images blue and takes away it's color. I don't know if I should increase one over the other, increase both, or just leave as is? When it comes to landscape type of photos, I generally add a little Saturation but don't add Color Temperature. However with photos of people, it's the opposite. When it comes to Sharpen, I think of the saying "Less is more". I'd say I would increase every image by 5%. Should I sharpen every image I have?