Creating a glowing tentacle abstract background

Start by applying gradient to the background layer.

Create a rectangle as shown.

Press Ctrl+T. Right click the layer and select 'wrap". Select "flag" from the preset warp shapes. Apply values as shown.

Double click the layer to open layer style window. Apply settings as shown.

Duplicate the layer twice with decrease in sizes.

Duplicate all the layer. Press Ctrl+T. Right click and select "flip horizontal".

Select all the layers again. Duplicate and press Ctrl+T. Right click and select "Flip Vertical".

Select all the shape layers. Press Ctrl+E to merge. Duplicate the layer.

From "Filter" menu select "blur>>radial blur". Apply settings as shown.

Select both the layers. DUplicate and rotate it 90°.

From layer menu select "new adjustments layers>> Hue/Saturation". Adjust settings as shown.