Hi everyone, as much as I tried, I failed to make some good dungeon wall tiles(for a game), so I'm asking for your help. I don't have any art experience btw.
First, I did this:

As you can see, It's plain, simple, boring.
Second:

ugly.
Third:

like a wave.
Fourth:

again, boring. Actually I used this image from Castlevania as reference:

but It's nowhere near to it.
So, I'm asking for your help, I read lots of tutorials already but I'm open to any tutorial suggestions, as long as It helps me to make better tiles. Actually I need all kinds of help, suggestions, please!
Thanks!