A space nebula I did a while back.
All of it was created myself except for the orange-green part in the center which was just a small low res stock nebula where I lowered its opacity to make it blend and changed its hue and saturation as well as contrast so that it fit better with the rest of the image.
There are a couple of parts that are a bit messy but I thought it was quite good for a first attempt.
Really like it! Maybe could have come more stars in the background around the edges?