I got some advice to tie the studies to my personal identity. So I started thinking of myself as “someone who studies Japanese”. Viewing it this way means that when I have free time now I think of doing reviews as a default option, rather than work or a burden that has to be done. I remembered that learning Japanese is a hobby of mine and I want to get better at it, so reviews should be an opportunity.
I started doing my reviews on PC only. I used to do them on my phone only, and the amount of time difference for text input was huge.
I am lucky enough to work at a job where I have a computer and am not that heavily scrutinized. So I started doing reviews during downtime at work rather than just trying to get them all done at one time during the day.
For me the mental threshold is about 100. As long as there’s fewer than 100 reviews I can generally do them all in one or two batches, but if it gets above that I begin to lose hope.
Edit: I’ll also add that compared to my fiance who also does WK, I am comfortable with an 88% review rate compared to her aiming for 100%. This lower rate allows me to be a bit sloppier and treat reviews more casually, and overall actually gives me a speed increase.