Never accept when the client (or sponsor or product owner or department head or whomever requires your design services) tells you to just do what you think is best "because you're the designer". Never. When you talk to your client or your team about the idea or the job to be done, you have to get an understanding of the most important things.
What is the goal? What is this thing supposed to do?
What is the context? Where will this live? What will this be used for? What is it dependent on? What is dependent on it? Who is the audience? Who do we collaborate with?
What are the parameters? What is the sandbox that we are going to play in? What are the rules of the game?
These need to be clearly defined. Before you start. Do not be told that you have to make it up as you go along. "If it could be anything it could be everything." Don't be guessing. You will be wasting your time, the time of the team and the time of the client. Don't guess. Ask. Ask again. Make sure everyone is on the same page. Interpretation is everything. Repeat how you understand things and make sure the client and team sees it the same way. Keep asking questions. Make notes. Listen. Understand the dots. Then connect the dots when you get to work. First is to understand and to agree on the dots. Now, set down the actionable steps. Brief the team. Delivery to the team and keeping them informed and making them truly part of this is the most important. Get them into clear roles and responsibilities. Agree on deliverables and deadlines. Be nice. Ask: "How does that sound?". "Does that make sense to you?" You're a team. Give them the space to say "no". You want your team members feel confident that they can do it. Ask "Does that sound reasonable?" A "No" answer is perfectly okay. Then you talk about it and find solutions. Your team is the most important when you want to deliver to your client. You can even go back to the client if there are things to work out or to clarify once you have discussed the project or task with your team.