What has worked for us is a chore-chart. Since two of ours are too young to read, I used pictures of things (went online to find pictures) like a bed for making their bed, a laudry basket of clothes to pick up clothes, a toybox to pick up toys, etc. Each day, they can mark off what they've done. I also included a behavior chart with it (green light - good, yellow light - warning, red light - bad). Each day that they do all their "chores" and have a green light they get an allowance - which we made 15 cents. They love getting coins!!
At night, right before bed we have "Clean Sweep" where everyone, all four kids (including we adults) go room by room and make sure everything is put away. Anything left out is deemed unimportant, and is taken to charity. They realize QUICKLY that they must put things away in order to keep it!
It also helps to have designated places for things like a family shoe area - we use a large rattan basket style box with a lid (no more hunting for shoes!) and a place to hang backpacks and put homework. For this, we hung a four knob hanger and above it, we mounted an acrylic 3-level tray for: "homework", "things to give to mom and dad" and "take to school."
Best of luck!