Hey, this used to be me. I will be honest,
TCLA premium resources helped me More than anything. You get access to successful apps and courses on how to write them and More. I swear im not sponsored! I know not everyone can afford it but if you can, I recommend getting it for one month and going through their courses and successful applications database. This really changed the game for me. I used to barely get past the app stage, whilst this year I got 3 ACs and had multiple VIs/second stage tests. Good luck!
PS. However, there are many free resources.
I think the biggest thing is to REALLY research the firm (I know this sounds generic) and to master your answers to basic questions like why law etc.