eco marking help

i need help how do i self mark properly please dm? m in y12 and i've been trying to self mark like everyone says to but i have like no time across all my subjects and i feel like when i do it for eco its so inefficient? like they just give you a sample answer how do i figure out if MY RESPONSE would also be full marks???

idk and i feel like it takes me so long that across my 5 subjects i would just spend a day self marking like there has to be a better way??