Separators are mostly used for forums but you can use them anywhere really.
I’ve seen it all over the place and saw a few tutorials for it, but I have an easier and a quicker way to do it. And honestly, it looks better.
1. Open Paint.Net and make the background black.
2. Add a new layer and make your primary colour white and your secondary colour fully transparent.
3. Now go to your Gradient tool and select Radial.
4. Go to your document and make a circle about the size of a silver dollar, then center it.
5. Make a new layer and move it under your second layer.
6. Select any colour you want. Make sure to choose a lighter colour. For example, if you want green, go with lime green.
7. Go back to your Gradient tool(that should still be on Radial) and create another circle. Make it a little bit bigger than your white circle. Center it.
8. Add a new layer and repeat steps 6 and 7. Make sure to choose a shade of your first colour that is a bit darker.
Note: You can add another layer of colour, or two, but it is not necessary.
9. Click on your first layer, Layer 2, and start to merge all the layers down. Do not merge anything with the background layer.
10. Go to your Move tool and pull the top of your document all the way down till your circle becomes a line.
11. Go to your Move tool again and stretch your line as much as you want.
Voila! You just made a separator! 🙂
Extra: Go to Adjustments and adjust the Hue/Saturation if you want to mess around with the colour.