I'm in a weird position in that I basically had to start over with my career this year. My sales gradually fell from 2014 through 2018 simply because I was lucky if I got one book out a year. When I did manage to publish, it was at random times during the year.
I can honestly say there are two things that work in getting reader eyeballs on your stories:
1) A new release triggers interest in all our other works.
2) Publish on a consistent and manageable schedule.
New releases doesn't mean a new novel every month. Put out a single short story or a novella in between bigger novels. If your schedule is too tight for new work, publish an anthology of previous short works, or a collection from a series.
When I say publish on a consistent schedule, post your publishing schedule for the year in a public place, like your website, and stick to it. You don't have to release a something every month.
And now, some of you are freaking. "But, but, SUZAN! You published nearly every month in 2019!"
Yeah, I did. Because I WROTE a good chunk of those books during the chaos of 2014-18, including during my stint with breast cancer. So it was a matter of finishing and/or polishing the new works this year.
And shit still happened in happened.
A Matter of Death was supposed to come out in June. However, my father passed away in May, and I knew the novel wasn't going to be ready because my headspace wasn't there. So if something major happens, cut yourself a break and don't beat yourself up over it. Let your readers know there will be a delay, and why if you're comfortable enough.
You'll find readers can be very patient when it comes to reader life rolls as long as they know what's going on.
Will I be releasing eight stories in 2020? That's what I've been trying to figure out over the last couple of weeks.
There's a couple of Justice Thalia short stories I've written. Do I release them singly, or do I write a couple more and release them as an anthology? Some readers want new Anthea novels, Others want new HERO books. There's a little paranormal mystery series I've been toying with. It's a spin-off of Bloodlines that has been nagging at me for several years.
So you see, I've got to figure out how I'm doing all of this. And that doesn't include a fun, one-off side project I really want to write, even though it probably won't sell a damn.
Back to my original point, release new content, release it consistently, and let your readers know when to expect it. And as always, YMMV.