HEY!! I SPENT SO LONG IN SCIENCE LAST YEAR!! Got a 4.5
So, here's what I do to really drill everything in my mind:
1.) Have two notebooks for science.
2.) In the first one in-class, write really fast, messy notes (because teachers talk FAST)- just make sure you understand them well enough for later!!
3.) Later, copy your notes nicely and neatly into notebook number two at home- use highlighters, pens, make 'em REAL nice :p
4.) Study and read your notes often.
5.) Spend lots of time on assignments, and understand the material- that means watching a few YouTube videos XD
Hope this helped a bit!! However late it may be...