Something that really helps me to be efficient is my lists. I have a ton of little notebooks each dedicated to helping me plan my day. Something I've noticed separates good students from great students is making lists, interpreting those lists into plans and checking off their work.
One of my most used lists is my to-do list. I can write up to 3 a day depending on what I need to get done. The best way to make a to-do list to me is to logically think of tasks from hardest to easiest.. For me, I like to do all the big things first and then combine all the small stuff later on. It may take a while but by getting the hardest task out the way, I free up some wiggle room in my schedule for all of the easier things that need to be accomplished.
Another great tip for lists is to do them in bright colors and color code them with the subject. I do all my personal lists in pink while school work is color coded by subject. I can write HW#3 in teal and know that it is IE 425. I also keep them all in a central location. I keep all my school related lists in my jumbo Lilly planner and my other lists on my iPad or in a notebook I carry everywhere.
My last tip is to use fun sticky notes and papers. I love anything by Knock Knock for specialized purposes. I have a pink All Out Of pad for my refrigerator that I use for grocery shopping. When I finish something that I want to repurchase, I mark it on the pad and grab the top sheet off the fridge when I leave for Trader Joes. It helps me a lot to not worry about if I forgot something for a recipe or totally do not buy milk for the week.
List writing is not for everyone. I have a friend who puts all his assignments in his Google calendar and that is a great management system for him. Whatever system you use, make sure it is consistent and something that makes you happy to use, not frustrated or confused.