Here are some more watercolour techniques and paintings for you to try!
Light to dark: When producing a watercolour piece, use the lightest shades of a colour first, then move on to a darker colour. Watercolour paint is not opaque, so if you painted any colour over back or darker colours, you woudnt be able to see it properly. This can be useful for painting gradients in landscapes, such as water, galaxy, or sunsets.
Brushstrokes: even when using black, think about the direction of the brush strokes. For jagged rocks, chaotic brushtrokes look more realistic, a galaxy needs more rippling/wavy brush strokes, and for sunsets usually straight horizontal brushstrokes work best.
Details: For details like stars, sprays of a thicker paint will work well, for grass or thin strokes, use a thin brush and apply shades of green in layers, starting at the back. For trees, use thin strokes for branches and small dashes and dots of paint for leaves. For rocks, use slightly thicker but alot more watery strokes.
Sketches: to incorporate watercolour in sketches, use it to emphasis one detail, for example the flowers on a tree, or the iris of an eye for a face. Within this detail, make the watercolour not too dark, and use mainly simple colours and not so many shapes, unless the ddetail takes up a lot of space, in which case you can do as much detail as you can and want to.
Abstract: some ideas for abstract watercolour are – lots of colours inside a jar, sillouhettes of random shapes with a watercolour background, swirling colours or blobs of colourful paint.
Landscape: some ideas for landcape watercolour are- sunset with a sun and the sillhouette of a tree or cliff (works with any natural background) trees next to a river (using rainbow blended colours for reflection makes a very cool effect) or autumn trees with translucent simplistic hills in various shades of orange and brown.
Here is some inspiration for you to try!