Saving flaps
Changing the direction you are flying will consume a lot of moves. Minimize this by trying the remember the course layout as it is previewed when each level begins. Roll down a slope to travel without expending flaps. There are many routes to the end. Sometimes a longer path that has downhill coasting is better than a shorter route that has more hazards that must be avoided through direction changes. After reaching the putting green, allow your ball roll to a complete stop before flapping closer to the hole. Squeeze into narrow openings to find shortcuts. Use longer and slower taps to travel further along longer open spaces.
Using the environment
Except for water and lasers other obstacles can be used to your advantage. For example, bounce the ball off the walls, rest it on sand, or use slopes to gain speed.