The first step is to add a new layer. Name this layer Large Bokeh or just Large. Select the Bokeh brush you’ve created following instructions in the first part of this post and paint approximately one third of all Bokeh you’d like to add.
The second step is to add another layer and name it Medium. You can downsize the brush a little bit, leave it the same size, or change the color slightly. Paint another third of Bokeh you’d like to add.
Next, add one more layer and name it Small.Paint the final third of Bokeh or less.
Now, the final step is to add blur to these three layers so that Bokeh looks authentic.
For the Large layer, go to the tool bar and Select Gaussian Blur under Filters (Blur). Set the Gaussian blur to around 1.8 and see the Bokeh spreading nicely.
Now, select the Medium layer and do the same thing: Filters>Blur>Gaussian Blur but set the blur value to 1. See the Bokeh in this layer changing but it’s defined better than the Large one.
Finally, repeat this process for the Small layer setting the blur value to 0.2 or 0.3. The smallest Bokeh should be defined the best.
If you like, you could add another layer and paint individual, well defined, larger Bokeh but that’s up tp you. And that’s it! It’s all about blurring!