There are times when you want to make large scale (global) changes to your painting. Things like overall contrast or color tint. Adjustment layers provide a fantastic solution for this type of challenge - and make traditional painters extremely jealous. If you're not familiar with the 'masking' I talk about in the video, here are three videos to clarify the subject: Masking 101 pt 1, Masking 101 pt 2, and Masking 101 pt 3
Hopefully you've already watched pt 1, because this video enhances the basic 'chop and warp' technique by modifying the selection. Quick mask mode, as shown in this video, can be a very efficient way to modify a selection! It is a very powerful tool, though many digital painters avoid it.
One of the real benefits of working digitally is the ability to be flexible. Want to change the color? No problem. Want to move something around? No problem. It takes a different mindset than traditional drawing, but if you can wrap your head around it your work will improve. This video explores the use of "copy merged" to modify a piece of nearly-finished concept art. Traditional wisdom says that once you've made it this far into a painting it's too late to move things around, but Photoshop makes it much more possible! Though it's always better to work out the problems in your illustration earlier in the process (ideally in the thumbnail sketch), you will occasionally need to make last-second course corrections.
As a followup to the Sketchup for Backgrounds mini-series, I want to explain the concept of a 'paint-over'. This is not an excuse to skip learning to draw, but rather a shortcut for experienced painters. Before digital art was possible, commercial artists have done plenty of tracing in their work - and it was totally acceptable. This was not because the artists weren't very good at drawing - it was merely a time saver which allowed them to meet their deadlines. Using a 3D render (from sketchup or elsewhere) is the same concept -- it saves time for the artist. Again, it's not a pass which allows you to skip learning perspective drawing. Update: In response to some of the comments about the Sketchup series, I've created a quick video which will hopefully clear up the confusion. View it here.
The goal of thumbnail sketching is to generate a large variety of design possibilities in a short amount of time. With this goal inmind, it's not 'cheating' to take a non-traditional approach. This video shows how to "built" your thumbnail sketches instead of simply drawing them. Using robots as subject matter, we'll first build a set of modular components, and then mix and match them to create a large variety of robot designs.
Sometimes the digital workflow will behave completely counter to the way you learned to draw with a pencil and paper. Though it might seem foreign and strange, I encourage you to embrace these new opportunities! In this video I'll show how to iterate through a set of thumbnails by chopping them up into pieces, mixing, matching, and contorting them. Though it's not much like traditional 'drawing', it's a lot of fun and can be a huge time-saver.