Creativity is fueled by constraints. The challenge is finding the right amount of information to get you started but not so much that you have no room to explore. Imagine sitting down to start a painting with no idea what you’re going to do. Then imagine sitting down to paint having made the decision to paint a duck. The second scenario immediately triggers associations and it’ll be faster to get into a state of creative flow.
If you’re working with a client who says ‘do whatever you like’ plan for extra revisions. You’ll soon find out that they’re aren’t actually okay with you doing anything. They just didn’t know what they wanted until they had something to react to.
Learn how to interview clients, and yourself, to establish the right amount of enabling constraints. If you aren't doing that now, try it, it will save you time down the road.