1. Be completely present.
I carry a little sketchbook around in my purse so I often fit sketches around waiting. Waiting for kids to get out of an activity is one of my main pencil sketching times. But when I'm sketching, I'm concentrating on sketching, whether it's a quick pencil sketch or a finished watercolor painting.
Your time sketching is yours. Enjoy life, don't worry about getting a project done, that you haven't done the laundry yet and you need that shirt or paying bills.
Sketching time is your time to fully appreciate life.
Think of sketching as meditation. You want to notice everything around you, be completely in that moment. You'll notice the smells, the sounds, the sights of that moment because that moment is what you're capturing on paper forever.
And that leads us to...
2. Look at what you're painting.
Don't paint to a formula when you're sketching. Or ever.
Green trees are rarely just green with brown trunks. Why do so many artist paint them like that? It's what they learned in kindergarten. Those early lessons stuck.
I know that if I have a light background, a dark midground and a medium foreground with some sort of light leading to the background (sunlit road or stream are favorites), the painting works.
It's not like that value pattern is a bad one. It works almost every time and really does look like that sometimes. Heck, the value pattern pulls the viewer into the painting and into that wonderful golden haze in the background. Lovely. Go through your favorite artists and notice how many paintings fit into that formula.
Now go through those artists and see how many of those artists have even 10% of their paintings with a different value pattern that worked. You know the really good artists now, not the ones painting to a formula.
Artists breaking conventional easy formulas and still making their paintings work, those are the artists striving for better work. Every time. Their work evolves with time, not stagnating into formulas.
When I'm sketching, what I see doesn't always fit that easy formula. If I paint what I see without trying to make it work as a painting, my sketch may be awful but my painting improves.
3. Learn something.
Plan on learning something new about your subject every time you sketch. Surprisingly, this isn't hard to do, but it is hard to concentrate enough to do. Think of doing yoga with the room humming "Ommm." I don't know where your mind goes, but my mind is somewhere else, probably doing laundry.
I have to yank my mind back to the present in order to learn from my sketch.
What you learn may be something simple such as how to do rough gray tree bark. Or the blue sky reflecting on muddy lake water. Maybe simply that you like using a dip pen and ink!
If you're noticing what you're sketching and not sketching to a formula, your sketching improves all the time. Every few sketches will improve - but you'll have some dreadful ones you just don't want to show anyone too!
That's all right.
Bad sketches where you learned something are way more powerful than formula sketches you got lots of likes for on Instagram.
So go out this weekend and sketch something beautiful. Sketch it from a different angle. Use a different brush. Sketch something you wouldn't normally sketch.
I think sketching something you love sketching but from a different angle is the easiest way to shake things up a bit and improve your sketching.
After all, you want to sketch things that you love. That way, you capture a moment of beauty and joy in every sketch.