People are most motivated when they own their job. When they are making decision and those decisions are valued. You need to lop off a piece of the project that each individual can own and then hold them responsible for it. You need to make sure that they have responsibility, accountability and respect. Also, get their back when they need it. When mistakes are made resolve them quietly and move on. Fear of failure is a great short term motivator, but is severely lacking in the long term. Knowing that the team will help you when you need it is what pushes people to take risks, try new things and push hard.
Teams are complicated because they are made up of people who are complicated. Motivating a team is elusive because the people on the team all have different agendas. For some people getting home on time is more valued than anything you could offer them as motivation. For some people it is as simple as valuing what they bring to the table. Get to know the people on your team. Ask them what drives them and make sure they have plenty of it.