Ideas for end pages

I would really like for the end pages of my book to just be purely decorative, a pretty pattern or design, no drawings or over crowded imagery, just something subtle as the contents will be busy and quite lively. The nebula images I previously uploaded have inspired these watercolour paintings by the colour, movement and space. Although the tones are much lighter and more dreamy I feel this works for what I am aiming to achieve and i quite like the effect...