To begin with, I have made writing a priority. Currently, my living situation allows me to work part-time so I can focus on my books. This isn't by accident but a decision I have made for this point in my life. This allows me to provide an appropriate amount of time not just on the writing itself but on social media and other forms of marketing for my books. This won't be forever but it's for now so it's up to me to make the best of it.
That aside, I schedule very carefully. Depending on my work schedule or what I have to do, I tend to organize my time so that I accomplish something every day. I get up early to write (6 a.m) on my days off or when I have later shifts. Scheduling the time is very important because if I waited until I 'felt like it' or when I'm 'inspired', there's a chance I would take a long time to write my books. Inspiration is when I jot down notes but writing time has to be planned around my schedule.
I write one chapter per day. I try to avoid stopping halfway through the chapter because it's very difficult to get back into the same headspace if I walk away and return later. Editing takes longer and is much harder to schedule because some chapters are easier to get through than others and of course, there are many rounds of editing before the book is sent off to the publisher. Meanwhile, when I'm finishing a book, I also have to start thinking about what I want on the back cover for a synopsis (I usually have a couple people assist me on this one) and of course, the front cover; what kind of image do I want? What colors work best? What will grab attention?
On days that I'm working or busy, I plan other things that are also relevant to my writing. For example, I might record or upload a video on a morning before going to work (depending on the time) or, at the very least, prepare and check social media.
Social media in itself is time-consuming. I'm on a few platforms so I must keep it up to date, check notifications and always be thinking of new things to add to keep things fresh. I'm on social media every day. There are some places that I focus more on but unless I have no internet access or am physically unable to do it, I'm on there every day working up a storm.
It's essentially up to me how much time I want to dedicate to my writing and therefore, it's also up to me to make the best of the time I have each day.