I usually do a quick sketch in photoshop, I'll also lay down flats and some rough shading. For Aiden I stayed completely in photoshop for the others I switch to Painter because I am more comfortable with the brushes. I like soft blending so I use large grainy blenders and a oily camel hair brush to get a slightly textured look.
[Edit to add: Wacom tablet]
I don't really have much of a "technique" I've got a long way to go to learn and I make it up as I go along. I try really hard to find a photo reference for positioning, foreshortening,and perspective. Sometimes I'll get different photoreferences and mock up a quick composite and sketch from that.
For color choosing I'll grab colors from photos of real people. When I try to grab colors from screenshots it's usually really purple, I think it has to do with the lighting on the ships.
So the process goes:
- Work big. I do 8.5x11inches at 300dpi. Smaller than that and I struggle.
- Save versions of the file every time I do something drastic like flattening.
- Figure out what I want to draw
- Find references to help me with perspective/foreshortening
- Take a ton of screenshots in game to try to get the "feel" of what the characters faces should look like.
- Rough sketch in photoshop on a separate layer (background is usually white for sketching)
- Cleanup sketch to make lines better and less scratchy, probably fix any weird uglies if I can
- Switch background color to the main color the photo is going to be, if you don't do that then all the colors you pick are going to look different in your final (well they look different to me, if you understand color theory then maybe you don't need this step)
- Choose colors, skin colors are hard so I grab them from photos and tweak them to fit my purposes. I try not to use too many colors, when you use too many colors in painter everything starts to look muddy when you blend.
- Make a new layer to lay in flats, I like to use a square brush that's too big so I don't get fiddly with details.
- Lay in shadows, I add shadows to the same layer, if you're not comfortable you can make a new layer for shadows but I run into mud problems when I do that.
- Make an extra copy of the sketch layer and flatten one copy of the sketch with the flats, shading, and background. You should now have a background layer and a sketch layer. The extra sketch layer is just a guide when you switch to painter. You can hide this layer and you may never need it.
- Switch to Painter, here's where things get creative. I use a blender (standard 20 px grainy blender) to blur the lines on the base layer. This is why I like to have an extra copy of the sketch layer so that if I need to check where a boundary should have been I can always unhide it to take a look.
- I pick out the colors that I like from the blending to add new shadows.
- Correct hideous structural problems that always arise. There's this part in every drawing where everything looks awful and you want to throw it away and start over, if you don't push past it you'll never finish anything. (Well for me, people who are good probably don't have that problem anymore but I bet they did at some point)
- Once you have your colors and shadows add highlights, blend when necessary, try not to overdo it (something I'm still trying to stop doing). add darker lines where you want to emphasize edges.
- Final step is to go to Deviant Art or CgSociety, look through all the work there and feel bad about myself
All of this is possible with photoshop but my version of photoshop is oldish and I already have my brushes set up in painter.
Here's a quick process gif sorry I don't have a flats only version but I failed at step 2 :P