I don’t use a sketchbook. I did years ago and I still have one of them but I rarely use one now. I decide what I’m going to do based on pictures that I have; either mine or something I’ve picked up on the Internet, then decide if I need more. Many of my works are amalgamations of several images. I’d like to give some credit to a photographer if I’m using their image but often I don’t have a name. If you are going to upload a photograph to the Internet then make sure your name is somewhere in the metadata. If I’m using several images it doesn’t seem reasonable to give credit to one. I often decide that a plant needs to be changed or something needs to be added so I will go out and photograph what I need. I’m presently working on a picture of a pelican. I don’t know when I collected the image and there is nothing in the metadata. I have flipped the image horizontally several times and I’ve probably done some colour and contrast manipulations as well. No metadata, and I can’t find the original image on the Internet. I’d like to give a ‘based on’ credit but am unable to. It’s amazing how many pictures of pelicans there are out there.
I use my computer as a sketchbook. If I’m going to modify an image I often do it quickly in Photoshop then print out an image. Printing isn’t very good (even if you have a very good printer it will never look as good as the screen image) I usually paint with the image on my computer screen where I can look at it while painting. The painting can’t exactly match the screen but it is better than using a printed image. You don’t have this problem if you paint from life. The computer gives a slight advantage in that I can tweak colours, saturation and detail somewhat but you can learn to do that from life too.
Getting back to sketching, I don’t do much preparatory work for paintings. Once the canvas/board size is established (usually what I have or what’s on sale) I grab a brush and start right on the painting surface. I am confident that after a few false starts and fixes things will start to appear. I’m showing an early image of Dying Swan here. This is as far as the sketching progressed before I started applying colour.