Sketch out and set up on its own layer, lowering the opacity to get it a level that doesn't impact the painting levels.
I set up the layer above the sketch as the details layer, above that I set up a layer just for the glasses as I'm feeling at this point I may have made them too exaggerated. Below the Sketch layer I set up the layer for the main skin tone. Just below that I set up a layer for the background colour for which I use a light blue.
Top layer - Glasses
2nd layer - facial details
3rd layer - initial sketch (will be discarded)
4th layer - skin tone (to allow sketch to show through above)
5th layer - background colour
The majority of the work is done on the details layer, building up skin tones. I hardly ever use swatches once a painting has been started. I may use the swatches initially to lay down colour but after that I primarily use the colour window and use the eyedropper tool grabbing colour that I have already laid down in the painting. I zoom in often to work on details and usually have the navigator window open to allow me to have a thumbnail view of the painting in progress. I also like the navigator tool for quickly zooming in on the working and reference images.
Though mot shown here, I decide the glasses are too big to allow an acceptable likeness so I adjust them smaller. Takes a bit of wrangling but I'm happy with the change.
One thing I am learning is that don't be afraid of mistakes and don't be afraid to change something. If you're not quite sure, save your file and "save as" a different file. Then you can compare which is a great tool when you are just learning... and I'm always learning.
After I'm happy with the look of the painting, I add another layer on top and fill that with a grey colour, add noise from the filter menu and adjust the opacity down to add a grainy feel to the painting. Add another layer above that for my signature (I don't want the grainy layer to affect the signature)
Again for your perusal, the finished painting. I hope you liked it. Feel free to comment with a critique or question.
Since I am now a full time cartoonist/caricature artist, I should really start to post more on social media and my blog. It's like going to the gym, we always make excuses for not doing it but know what the benefits can be if done properly.
I have a sign taped to my wall above the computer that I'm writing this at that says... Tuesday is Sketch of the week day... so today's sketch is of a good Canadian kid.
January 10th, 2017
Digital drawing, created in Autodesk Sketchbook, drawn on my studio Cintiq21ux (still running after 6 years).
Hope you enjoy this drawing... back to working on commissions.