Make a Photo Sharper and Brighter

Before:

Click to enlarge

After:

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Press Ctrl+B to go to Color Balance and set something like the picture below:

Continue to press Ctrl+M to open Curves and do like this:

Press Ctrl+L to open Level:

Go to Image -> Adjustments -> Selective color:

Use Brush tool to spray over the sky, set color #O3C4F9, Mode: Soft light, Opacity: 50%, Flow: 50% you will get the result:

Go to Selective color and set something like this:

Continue to use Brush tool to spray the grass area (color #D29609), then go to Selective color:

Go to Filter -> Sharpen -> Unsharp Mask

Go to Curves:

Go to Filter -> Blur -> Surface blur

And this is my final result, the picture looks sharper and brighter:

Click to enlarge