In A.D. those tapered black shapes can be generated with brushes - you must use either drawing velocity control for the brush size or make it pressure sensitive. That needs a drawing tablet. Both needs careful brush settings and really plenty of practicing.
Another approach is to prepare one straight horizontal tapered stroke as PNG image with transparent background and use it as vector image brush. It works also with stiff hands. An example:
On the top there's a filled shape drawn with the pen. I saved it as PNG. I defined a new texture image brush from this PNG file. You can see my brush in the brushes collection. The rest of the shapes are random vector paths drawn with the pencil. The new brush is applied to them.
(Not asked: Illustrator users simply drag their shapes to the brushes and start to use them. The result is a vector, not a shape which hides a bitmap.)
All said above is valid also for droplet and spatter brushes. You must control size and flow with velocity or (preferably) with pressure. You can also paint the dots one by one - slow, but gives full control. A compromise is use randomized brush size. The next pattern is made by clicking the mouse one time per dot:
The brush is the most basic round one available in the bitmap persona (=working mode)
The next is made by painting a few strokes forth and back randomly with the same brush, but by having a wide randomized spacing:
If you insert more randomized parameters it starts to resemble spraying.
But the base shape stays. There's no such thing as sprayer which takes shapes randomly from a collection.
In A.D. you can insert path nodes by clicking with the node tool to create easily some edge details:
Note that in A.D. you should be prepared to accept bitmap shapes mixed with vectors. If it must be pure vector or you do not have especially well trained painting hands Inkscape may fit better for your purposes. There you can find far more vector tools and also the wanted shape sprayer.