Whenever you are hanging around in the area or have some free time to escape and do something different make sure you get some food (7 Eleven Chocolate Muffins are THE BEST) and head over to the beach. I like to take a small blanket to lay in the sand comfortably.
St Kilda is a very vivid place. Luna Park, restaurants, skaters, families and random people make a special environment that combined with the breeze and the sound of the ocean really help clear your mind. St Kilda is always full of seagulls and when they see you with food they come to you. At the beginning they are always shy and scared but after a few minutes they won't let you go! Hide your food and throw some at them in the sand. The more you repeat this the closer they'll get to you.
It's funny, mind clearing and very enjoyable.