it's mostly possible because I've changed the way I solve, focusing more on better F2L solutions and ultimately, decreasing the amount of time I spend on F2L. I haven't really started planning first pair, but now I find it easier to track the next pair while solving one. There's also the fact that I upgraded my main, it used to be this really clunky, grimey RS3M 2020. It just wouldn't turn.
To be fair, I haven't been practicing in the last few days - owing to school and whatnot. And I've been learning full OLL, so it's pretty much slowed me down by a bit (more time for recognition). I average 15-16 seconds with all the new OLL algorithms I know, but I think it's better that I inculcate this habit from now instead of struggling later.
In late February, I was really out of practice. By a lot. I was averaging 19-20s (which, for around a year of not cubing at all - is pretty good). From the day I re-opened this thread, I was doing nearly 150-200 solves a day, which, by some measures is not a lot. However, these were just the solves on my main 3x3 session. Throughout the day, I was grinding out slow solves, trying to do so without pausing, at all. I also have this really bad habit of just spamming algs while studying (I should quit that). In addition, I had separate sessions dedicated to PLL and F2L, two of my weak spots.
Now, I cannot say just how effective this would be for other people, but I have struggled with pauses and lockups due to me trying to turn too fast for my own good. I also learnt a few alternative, faster algorithms for some PLL cases and some important F2L algs (I was mostly doing intuitive beforehand).
I think these have been the biggest contributors to my increase in speed.