Have a clear vision, set your goals and be firm with those. Clear goals keep you focused, confident, motivated and on track.
At the same time, be flexible with your strategies of how you will reach those goals. There are many ways to get to your goals. You can start with well developed plans, but then life has a way of changing things up. You may have to – probably, will have to – pivot as you move along toward your goal. If you recognize in advance that you may have to shift your strategies as you move along, it will be easier to actually shift.
Keep your eye on the goal, but remain flexible in your path to it.