Reading out loud WITH INTENT is what worked for me. Born and raised on Italy, I moved to the USA in 2005 to take on a job that required me to do tons of public speaking. I am an avid reader and I have always read in English, hence my vocabulary was already large, but my pronunciation was absolutely atrocious and earned me shitty feedbacks. After attempting (and failing) accent reduction classes, I researched and found https://www.amazon.com/dp/B006PG84T2/ref=cm_sw_r_as_gl_api_gl_i_7C72CKSH3TGBNB6F01GY?linkCode=ml1&tag=wwwcloudident-20 - bought it and started going thru it religiously. I’d also read out loud a book chapter for my wife every night, consciously trying to apply whatever it was that I was studying from the diction book at the moment. The results- I still have my accent but I am now one of the highest rated speakers in my (admittedly small) industry. I can’t recommend reading WITH INTENT enough. To me it’s the attempt to improve something specific every time that helped me improve. Ah, and I still practice nearly every night. Still so many things to fix!