How do I improve my writing?

How do I improve my writing?
My grades in AP English have been so unpredictable. I range from getting D’s to A’s and I really feel like my essays are only about the same. This is a pretty vague question, but how do I improve my essay writing? xD

talk to your teacher.
her grading techniques sound a bit unbalanced.
is she giving you feedback when she gives you a D?
i had a professor give me a B on a paper once, and she made absolutely NO corrections. i spoke with her after class and asked her why she gave me a B when she had failed to mark anything as incorrect. i wasn’t trying to get a better grade, but i wanted to know what was wrong with my paper so that i could improve upon my writing for future papers.
she ended up giving me an A. her only complaint was that she knew that i was an excellent writer and that the paper didn’t match up with my potential.
i would suggest taking all of these essays to your teacher and asking why your received the grades that you did.
if she isn’t giving you adequate feedback, that is the problem. the only way that one can correct their mistakes is through CONSTRUCTIVE CRITICISM.
if she gives you a reasonable explanation as to why she gave you the grades that she did, ask her for extra help or consider enrolling in a writing workshop.
good luck!