I seem to have started something for myself with the book I mentioned in a post back in March. When I take a digital photo now, the first thing I do before I use it, is to just see if a better image can be "developed" by using blend modes rather than simply individual tools like brightness and contrast and opacity levels.
The book I found in a charity shop, inspired me to start playing around with the blend modes but it is rather like a cookery book. The author himself actually calls the examples recipes, and gives settings to explain the results on the photos which he shows. Great for showing what you can do - not so great for explaining what you do to achieve a required effect. I started looking around on the internet using Google and lo and behold, as you might expect, there are lots of great tutorials. Some are just a little too technical with lots of maths, but bookmarking one or two is well worth while for reference. I would recommend
Photoshop blend modes explained to understand how they work
Photoshop’s Five Essential Blend Modes For Photo Editing, a brilliant article explaining how to use the blend modes to achieve a desired effect
Photoshop, using blend modes - a little more complicated usage but well explained.
I am sure that a quick search will bring up many more, of which, you may find your own favourites. There is a mixture of ( fairly complicated maths), what they are, what they do and how to use them in all of the articles and your own requirements will colour your choice. But for now, take a look at how I improved this simple macro-photograph of an amaryllis flower.
Quite a decent shot but I prefer a little more contast in my images, a personal choice. So I looked at the blend modes which serve to increase the contast. After switching through those half dozen modes, I decided to go with "OVERLAY" which gave me the results as follows:
I thought this bought out the scarlet of the petals whilst darkening the centre of the trumpet. If I was looking for a botanical image then the first is going to be best because more detail is seen in the shaded centre of the bloom. But this was to be purely for effect, so I went for it.
I also edited the shot to reduce the information in the background here. I selected the flower using the magic wand tool, setting a high tolerance and adding small areas by shift +clicking until the whole area was selected. I then inverted the selection and used image/adjustments/hue&saturation to give the effect which I was after.
But the flower then seemed to be floating rather then existing in the scene, a last touch was to copy the stem and paste into this image.
A small touch but it worked for me.