Design a classy and inviting book cover for a journal

The 12 Step Journal: Using the Tools of the Program, One Day at a Time, for Recovery and Serenity

Dan Alamehmet

The author's details won't appear anywhere on the cover

This is a journal, for people who are recovering from an addiction using the 12 steps, for example alcoholics who go to Alcoholics Anonymous. Each day, the person will complete one page of the book, writing down their thoughts and feelings, and answering some questions. This process will help them in their recovery.

Adults.
Both men and women.
People who are recovering from an addiction - for example alcohol, drugs, gambling, sex.
Typical age range would be 25-70.
The book will be sold in the US and the UK

I would like a fairly simple cover that is attractive and looks luxurious. I am completely open and inviting of all ideas, but I envisage a fairly simple coloured background, with the title and subtitle foil stamped and embossed, in attractive, classy fonts.
The design must be unisex as it will target both men and women. I want to convey a feeling of value, that the journal is special and inviting, that you want to touch it, open it, write in it and value it.
The cover will be a flexibound cover (somewhere between a hard and a soft cover).
Dimensions:
Front and back: width 7.125in, height 10.25 in, each
Spine: width 1.25in, height 10.25 inches

I don't know what colour(s) I would like, so would like to see ideas. It will be sold on Amazon so needs to look good when shrunk down to a thumbnail.
Also, in the future, it may be that I create variations of the cover - the same design but with different colours to give people a choice. Therefore I would like the design to be easily changeable to other colours.