A few things have really helped me be productive writing (and I’m not wildly productive, but I’ve submitted at least a couple first authored papers each year, and then been a coauthor on at least two others each year, so definitely an OK pace for right now).
1) being in a writing group! My PIs organized one, but students could also organize one. We all do something with behavioral health, but within that our areas are pretty different, so it’s not essential to all be writing on the same topics. 2) in our writing group we have been reading (very slowly), discussing, and using the tips from Sarnecka’s The Writing Workshop (pdf is available out there somewhere but here’s the Amazon link to take a look at the description): https://www.amazon.com/dp/1733484604/ref=cm_sw_r_cp_awdb_imm_B33YB9D7FB23MEH4Y3W8
3) a group writing log! I don’t write in the log every day, but every few days I catch up and put down whether I wrote or not each day for the previous few days. I do write almost every day, but literally one minute of writing counts as writing that day. Maybe I added a tiny bit to an outline, maybe I got into stata and fixed something with my analysis, maybe I just tracked down a citation I needed and stuck it in there, or maybe I wrote three pages - it’s all over the place. But having the group accountability of the log, AND seeing my progress written down on the log makes me feel much more on track.
4) regular (weekly) check ins with my advisor and regular writing groups (every other week) also keep me on track and give me a rhythm to my week. I don’t do great without some structure to my schedule, even if that structure is self-imposed and I kind of need to make it up every week after my meetings.
Obviously everyone is very different! This stuff has worked for me to make me modestly productive as opposed to totally unproductive and stuck :) hopefully it’ll help you rocket into the modestly productive realm too!
I'm glad I could help! If you've got the time, I find that stream of consciousness exercises are really helpful for warming up prior to working on assignments. Before writing something, I'll just pull up an empty word document, look away from my screen, and just type everything that comes into my mind. No backspacing allowed, and I just delete whatever I wrote afterward. It's an excellent way to get into the writing mindset and preventing that lockup.
Here's some other resources you might find useful, these books were really helpful to me as well:
Hope these help!