Being random can be really hard if you're a human. It's technically impossible for a computer, but they still seem to make it look more real. If you struggle being random, this tutorial will help you achieve that random scattered look.
You can either use this method with an actual brush shape, or just use a basic circle and then cover them up with elements after.
First you will need to select the brush tool (B).
Then, over on the right choose the Brush Palette. If you don't have this options go to Window -> Brush and it should pop up.
This brush palette will give you a crazy amount of control over what the brush does. I am going to focus on settings for making a random scatter, but it's worth clicking around and seeing what else you can do in here.
To start, change the spacing, to make each brush further apart. This means that even if you click and hold down while dragging your mouse, you will still only get your brush with space in between.
Next, choose the next tab "Shape Dynamics." Again, there is a ton of controls here you can adjust, but I'm just going to use the first one which will alternate the size of my brush.
Choose the next tab, "Scattering," which is where things will start to get nice and random. I'm just going to adjust the first option again:
Finally, you may want to go back and adjust your spacing depending on how dense you want your scatter to be.
Now you're ready to go make a scatter. Make a new layer and drag your mouse across the canvas. Viola! Use any brush shape, or just use it as a template to know how to be random.