Start by creating a new document, background layer with black, alternatively you could use a dark gradient instead. Click the brush tool (B) then change the settings of this brush to a 1px round, white brush with 0% hardness.
Create a new layer then select the pen tool (P) and in the main toolbar make sure paths is selected, now start slightly outwith the canvas on the left then using about four points draw a curve with a similar shape to the one below. Right click anywhere inside the document then select stroke path, make sure simulate pressure is checked then hit OK. Lastly hit the Esc key twice to get rid of the path.

Now hold Ctrl and click on the layer with this curve in it, in the layers panel,
Next go edit>define brush preset and save that curve as a brush.
You can now hide this layer by clicking the eye next to it in the layers panel.
Select the brush tool again then bring up the brush settings by going window>brushes.
Choose the brush that you just made then use the same settings as below.

Create a new layer to hold our lines. Okay we now want to use this brush to create the lines in the picture so first drag from the left of the canvas to the right until you end up with something that resembles the image below. Not that each line is slightly different, this is because in settings we made it change angle and roundness.

Now we will make the lines glow so right click on this layer in the layers panel then select blending options. Use the settings shown below

Structure :

Blend mode : Normal #BD016B
Opacity : 76 %
Angle : 120% check Use Global Light
Distance : 0px
Spread : 0px
Size : 0px
Contour : Half Round

Outer Glow Setting :

Blend Model : Normal
Opacity : 100%
Noise : 0%
Set color for glow : Spectrum
Technique : Softer
Spread : 0%
Size : 21px
Range : 50%
Repated Same setting again

Now create a new layer and select a large soft brush then change the foreground color to a bright color and brush some random shapes. Repeat this with a few diifferent colors to end up with an effect like this.

Next go filter>blur>gaussian blur and use a value of around 100px then change the blend mode of this layer to color. I’ll let you decide what opacity this layer should be but I used about 50%.