I always love seeing other artists' sketchbooks. They reveal a lot about the artists' thinking process that is invisible in his/her finished paintings. They tell us about how the artist begins to solve problems long before the brush touches the canvas. Often, they're just practices and exploratory sketches, and those too, can show us glimpses into the artist's mind.
I don't know what my sketches show you, but they're interesting to me. I usually don't remember when or under what circumstances many of these sketches were made - I just have so many of them and I don't remember to take written notes about the figure sessions or locations. But that's OK, I don't find those kinds of documentations relevant in these.
I like to draw with a pen. I use a regular steel tipped writing pen readily available at Staples. Uniball or some such common brand. I like the pen because you don't have to sharpen it. And it's darker than a pencil lead. If I make mistakes, that's part of the drawing. I like to see mistakes and struggles. They're more interesting than perfect drawings.
The pen also forces you to commit to your lines. It forces you to be mindful, and the intention will show in your lines. The pencil tends to allow you to be less committed, it allows you to be timid and unsure (Not that you are timid and unsure, but if you were, the pencil drawing will reflect that.)
You can see that my lines aren't perfect. It often takes a few tries to get the contour in the reasonable range. Even then it's not accurate. Then again, precision and accuracy of the outline is not what I'm looking for. I'm interested in communicating the gesture (if I'm drawing the figure) so if I can capture something of the essence of what the body is doing, that's more important to me than copying the figure in front of me. I look for, and push the "flow" of the gesture. It's what makes a figure drawing more fluid, graceful, and it has to be imposed upon the drawing. You can't achieve fluidity and grace by copying the model. The priority must be clear, or it won't happen.
When I don't have a figure model, I'll draw cars, trees, chairs... it doesn't matter. Cars are hard to draw. You have to draw them more or less accurately, perspective and all, for them to be convincing. As they are a big part of cityscape paintings, I can't neglect practicing drawing them.
Sometimes I use markers. I only have three or four but as I keep the value structure very simple, I don't need a whole lot of makers. I wouldn't know what to do with them, anyway.
The one thing I don't like about these markers is that they bleed through the paper on my Moleskine sketchbooks, so the flip side looks terrible. I like to draw on every page, so it seems a shame to have marker bleed through to ruin a page with decent drawings–but I do it anyway.
Non-alcohol based markers, such as Tombow won't bleed through, so may be I should be using those. There are also sketchbooks which have no-bleed marker paper, but I've yet to try them. I still have a few Moleskine sketchbooks to work through before I can spend more money on sketchbooks.
I do like how the marker indication quickly creates a sense of light and shadow. The trick is to be decisive, and don't go over the same are more than once or twice.
Some plein air thumbnails using markers and pen. A good way to get a quick look at value organizations.
Drawing in sketchbooks is a great way to practice when you don't have a lot of time or if you're not in your studio. You can carry a sketchbook around wherever you go. All you need is a pen to draw with.
Five minutes while waiting in the parking lot for you child to get out of school? Draw a few cars! Ten minutes at Starbucks? Sketch people drinking coffee and staring at their phones! The opportunities to practice your craft is everywhere. You just have to do it.