We do a lot of free play here, I would say we spend a total of 1 hr a day or less doing adult-led activities. Some kids I've had are better at playing than others but they have all caught on eventuallyI have always had mixed ages in my group which really helps.
I also rotate toys but only the bigger ones....but I do use our everyday toys when I'm doing activities with the kids so it will spark their imaginations and give them new ways to use our same old toys. Like if we are learning about ponds we will dig through our animal bin and pick out all the creatures that live in a pond and use them for counting, games, sensory bins, etc. Something as simple as cutting out a piece of blue paper in the shape of a pond and adding it to the play area will suddenly make those animals that were forgotten in the bottom of the bin seem super exciting.