Hello, Codeforces. After spectacularly losing CERC, I've decided that the only way to advance further is to reach 2600.

So I'm interested to hear about the best/fastest/most reliable techniques to reach IGM. Should I upsolve at least one task each day, or should I focus on upsolving full contests; should I pick tasks by difficulty, or should I even upsolve atcoder's Div1 and AGC ? Should I force myself to follow a schedule ? For individual tasks, should I try to solve them for a fixed amount of time and then read the editorial ? Is it okay to extend the time if I feel close; is it okay to stop the timer earlier if I feel that I have no clue at all ? Is it okay to spend a day on a single problem ?

Or is everything worthless, and is it natural talent only ?

UPD: not to be rude, but I am more interested in taking advice from people who have reached this rating, so they can share their routine and struggles.