First and foremost STUDY before you go to the airport
While studying at home write down all your questions and come prepared to ask your instructor when you show up to the airport. You will learn more as an engaged student asking questions versus a one-way discussion where the instructor preaches aeronautical theory for an hour.
Fly regularly
Unfortunately flying is not like riding a bike. There are too many things that must be kept fresh in a new pilots mind and if they do not fly often they will be lost and have to be re-learned. You should commit yourself to fly at least two times a week. Flying is easy but earning a pilot certificate does take regular practice.
Become an airport geek and get to know other pilots!
Aviation is a tight-knit community. Knowing other pilots has its advantages such as meeting an aircraft owner who you can learn a lot about aviation. Also knowing people around the field you might land your first job since many flying positions are not posted publicly and are word of mouth.
Flight simulators
Flight simulators are especially great for learning instrument procedures since they can reset an approach in a matter of seconds. This allows a pilot to fly several more instrument approaches an hour versus just 1 or 2 in an aircraft. Also, this time in a simulator is significantly cheaper than flying an aircraft and counts towards required hours to complete the private, instrument, and commercial certificates!