I don't bother much with KDP select anymore, as the changes in Amazon's affiliate program has made free giveaways less appealing to book bloggers; their affiliate codes don't bring in the cash anymore.
Unfortunately even if you're not in it for the money a steady production schedule is the only way to keep visible. Amazon heavily weights its search results towards new releases. If it takes you a year to publish another book, well, by the time that year has past your first book has been hidden in search obscurity for 10 months.
There are only really two things I can suggest.
Be prolific. I strongly suggest the book 2k to 10k; it's about doubled my productivity and even if you can't do everything the author suggests, it might have a tip or two that helps you.
Write quality content. Someone once said that every writer has a million words of trash to put out before they can write a single word of gold, so keep writing. Write every day, even if it's just a thousand words. Practice makes perfect, right?
Anyway, good luck.