Early in a level, focus on repairing Sawmills and Farms . The passive income they provide is much more efficient than gathering individual nodes.
Every action (clearing stones, repairing bridges) costs specific resources and time. Tips for Getting Gold Medals Northern_Tales_5_Revival_Collectors_Edition-RAZ...
Ignore unnecessary resource piles once you have enough to complete the final goal. Early in a level, focus on repairing Sawmills and Farms