I'm always reading that I should wear two different shades of foundation. I understand why (because people are generally not all one colour and it makes for a more 'realistic' looking skin tone), but I have no idea how to apply two different shades and where I should be putting the darker shade/which parts of my face?

I always apply foundation with my fingers and then blend using pads to get it into any little nooks I may have missed and to smooth it out, I wear Mac studio fix NW50.

Can anyone offer up any tips?