Any suggestion would be highly appreciated!
First of all, it seems like they have a gradient swatch applied to the stroke, from red, to gold, to yellow. Then the line is not a brush stroke, but rather a pen tool created line with a nice bezier curves. Last you could go to effects and add a bit of outer glow to the layer. I am not an expert in Ps but that's what I would doI think you could put all object layers into one folder and apply the effect to all at once. But I think the gradient is most important to make them look alive. Try that?
They are half-circles which are rotated and stretched. Their color is not constant and everyone is a little different. Others have already suggested gradient strokes, so I try something else.
Creating and deforming them to right sizes and placements is a little easier in Illustrator, but of course Photoshop shapes are ok. I started in Illustrator, but moved them as bitmaps to Photoshop for coloring: Here's an Illustrator screenshot:
Draw a circle
Clip half of it away (=use direct selection tool, select the lowermost anchor and press DEL)
Duplicate, move, scale, rotate and stretch until you have the wanted arcs. Have a reference image below for the placement (not used here)
Make white copies of the arcs and copy them to the clipboard.
Goto Photoshop. Start a high resolution image which has the wanted background (here only a full black)
Paste the white arcs as pixels to the Photoshop image. Scale , if needed. A new layer appears. Copy the generated bitmap to the clipboard (=select all, Ctrl+C)
Shut the white arcs layer. Add a new layer and fill it with a color gradient or preferbly make some more complex colored pattern. Now you have:
Give to the gradient layer a layer mask. Goto layer mask onscreen edit mode by selecting the mask icon in the layers panel and pressing Alt at the same time
Fill the mask with black, paste in place from the clipboard the wihite arcs.
Click the layer content icon and you get the arcs as colored:
Add a glow effect as a layer style, if you want more richness:
- the result is bitmap, but the gradient and the layer style are still editable.
- I have drawn quite thick lines, but those in your example are thin, many of them only 1 pixel wide
- the coloring in your example is complex, probably a painted pattern, much more complex than a gradient.
- this all is possible in vector domain for best reusability - no matter do you use Illustrator or Photothop.
The following screenshot is from Illustrator. Gradient is clipped with Transparency mask, which is a grouped copy of the arcs (here white).The glow is a blurred, red colored copy of the arcs: