Season planning works best when it creates options instead of locking every day into a rigid schedule.
Use each season as a planning window
Set a few useful goals for the season rather than trying to optimize every day.
Match crop size to your daily routine
A larger field only helps if watering and harvesting still leave time for mining, fishing, relationships and exploration.
Keep some money flexible
Do not spend every coin immediately. Flexibility makes upgrades and opportunities easier to use.
Review at the end of each season
Look at what became easier, what still consumes too much time and what should change next.