Final answer:
George Washington was the first president to appoint cabinet members, recommend the title "Mr. President," and set the precedent of serving two terms.
Step-by-step explanation:
The president who established these traditions for the executive branch, such as appointing cabinet members, recommending the title "Mr. President," and being the first to serve two terms, was George Washington. Washington's actions set precedents that would shape the role of the presidency moving forward.
He created an advisory group known as the President's Cabinet, which consisted of the most senior appointed officers of the executive branch. By serving only two terms, he set a tradition followed by his successors until Franklin D. Roosevelt. The title "Mr. President" was his preference to ensure a balance between respect for the president's role and avoiding monarchical implications.