1. Create your layers
Once you’ve applied all other necessary edits to your image, create a new image layer to sharpen. Do this by selecting all your layers and pressing shift, alt, cmd and E to merge to a new layer. Duplicate this new layer twice, naming the top one ‘sharpen’.
2. Convert to Smart Objects
Click on the top layer and go to Filter>Convert to Smart Filter to change it to a Smart Object. You’ll find a little icon appear on the layer in the Layers palette, later you can double-click on this icon to re-edit the filter settings you apply at any time.
3. Apply High Pass Filter
Activate the ‘Sharpen’ filter and go to Filter>Other>High Pass. Your image will turn grey but as you move the slider you’ll see the edges of your image that are becoming sharpened. Set the slider to approximately 9px and click OK.
4. Refine your sharpening
Change the Layer’s Blend Mode to Soft Light or Overlay, depending on the strength you want. Add a Layer Mask and press cmd I to invert the mask to black; use the Brush Tool with white paint to reveal areas you want sharper. Reduce the layer’s Opacity too if too crisp.
Applying High Pass filter is just the beginning, once you’ve edited your Layer Mask double-click on your Smart Object and re-edit your sharpening in real-time to find the perfect balance.