First, BRAVO in taking charge. While he may be the team lead, you are a professional, and your question shows exactly that.
Clear Expectations. You need to understand what he wants. You need him to understand that you're trying to give him what he wants, but that he needs to articulate expectations.
I've been utterly astounded at the mess that can result without these expectations: When the company wants predictability, and NOT productivity, you need to provide that (e.g., your schedule time estimates should be three-standard-deviations). Medical systems and defense contracting projects are like that. When the company wants innovation, and is willing to forgive many sins (schedule, features, etc.), you need to embrace/understand the industry and think creatively.
Seriously: Clear expectations by both sides help ensure you, as a professional, deliver what the company wants.
I've seen situations where the developer delivered an anti-gravity device that generates free energy and makes hot sandwiches using only rain water, and the company was pissed that it was done in analog, not digital. (At the time, they asked for a toaster that would fit bagels.)