
This step-by-step tutorial is just supposed to show MY way of doing things. Other artists do it differently and also get wonderful results. But if you're new to watercolor, maybe you'll find this kind of useful.
Since this is a tutorial, I grant you explicit permission to copy (and upload wherever, although credit for the original would be nice in that case) the image for practice purposes. Just don't make any money with it. ;) By the way, the plant is Chaenomeles japonica.
Okay, so... Here it is.
1. I made a clean pencil sketch on watercolor paper. In this case, because of the small format (ATC) and the detailed picture, I used very smooth (hot pressed) paper. I skipped the part with preliminary sketches for composition and light/dark (on cheap paper, of course - I throw them away afterwards), but I do them before I start a serious painting. I think it's a good habit to do so. On the "real" painting, I only draw the contour-lines of objects with pencil.
2. I start coloring with the yellow layer. I always use the yellow first, because watercolor yellow is VERY delicate and muddies easily when you try to lay it over other colors. Also, this is a first way of determining where the light will go in the picture. Although the yellow is overpainted almost completely in the end, it gives a warm glow to the parts in sunlight. The brightest spots, I leave white.
3. Then, I start defining the shadow areas of the picture. For this, I use the complementary color of the light. (This is a fairly important principle you might have heard of: warm light - cool shadows, and vice versa. I think Leonardo da Vinci was the first guy who wrote it down, haha.) In this case - purple. This is also overpainted almost completely in the end, but changes the characteristics of the upper color layers.
Now - and this is important - I let the paper dry really, really well. (At least a day is necessary.)
4. I roughly put in the characteristic colors of objects. This is simply "the flowers are red, the leaves are green, yadda yadda". Note how the lower layer of yellow and purple makes it already look pretty differentiated!
5. Now it's time for some detail, and also for further darkening of the shadowy parts. I make sure all tonal values from "white" to "almost black" are present in the painting. This is important: too light shadows tend to make a picture look flat. Also, the human eye will be inevitably drawn to the area of highest contrast between light and dark. This is a nice and easy way to define the focal point of a painting. (In this case: note how the light on the lowest petal borders on a dark shadow area? I bet this is where you looked first!) I also pay attention to all the textures, like the veins in the petals.
6. Finally, I add some last details with opaque white. In this case, the brightest reflections of the light, and the veins of the leaves.
Finished! If you have any questions, additions or other remarks, just leave a comment.