Probably my best cover so far c:

Images

This is the background, which I blended using various images on Pinterest when I type in "space".

And the images~

Editing: Superimpose

First added in the boy:
Blending mode: Normal 95-97%

Girl:
Blending mode: Normal 95-97%

Lusamine:
Blending mode: Normal 95-97%

For all of them, I used the regular brush at 100 softness to clean up the edges.

(Yeah, my new style pretty much uses little to no blend modes.)

When I added Solgaleo, I didn't erase it very cleanly to the very edges. I erased enough to look like there was energy coming off him, looking natural and blended with the rest, using soft brush. And because I was lazy.

Pretty much the same with Lunala, I erased the parts that covered Solgaleo's face and blended it in with soft brush.

Text: Phonto

Embroiled, Deeceit: Annabel
Authors: Chocolatebox

Text Textures: Superimpose

I used the background and covered it over the text, then used blend Mode lighten at 100%. First I erased the all of the overlay. Then, using the eraser (Revive), I traced over the letters. Once it's all filled in, I used my soft brush, at full softness and size, I quickly and in one stroke erased the texture. If you did this correctly, you get a softer version of the texture but just a beautiful.

Filters: Picsart

These are the effects I used, although not in order.

Filters:
Seafoam - 70
Film - 70
Lomo > L4 - 85
Sharpen - 85
Drama - 80
Dodger - 45
Artistic > Motion - Distance 100, Fade 80

... That's a lot :p

Final Result

I hope this tutorial was useful! You can request any cover tutorial within the week it is posted, although maybe less if I have already deleted the images.