For biology, I found watching videos, making my own notes, drawing up diagrams and teaching myself in the mirror really helped.
With Italian, I found some websites were you could communicate with people who speak the language you're trying to learn who are trying to learn English. It was simply a matter of practicing and practicing and practicing with them.
I think to really learn effectively you have to appeal to the three ways of learning: visual, auditory and kinaesthetic.
Visual: watching videos, looking at/making diagrams, tables, etc.
Auditory: Reading your notes out loud, listening to the teacher in class, teaching yourself out loud.
Kinaesthetic: Making it happen, whether that is by twisting the words and saying them out loud to yourself in a different way, drawing, making hand movements that describe what's happening. For example, I learnt the methods of xylem and phloem by performing what happens with my hands.
Hope I helped!