1.Plan ahead (money won't be a problem) by making sure your farm is well stocked
  for the next day (especially before Farmer's Market). Make sure produce that 
  can be stacked is full (like milk, ketchup etc) before completing last order.
2.Get multiples of animals/machines to increase production capacity. Bee hives 
  take up little space but honey sells for $500 at farmers market!
3.The move button is your friend! Use it to micromanage your farm - move crops 
  that need watering/replanting nearer to the well/seeds so that you don't have
  to move as far. Later on with the sprinkler, have one sprinkler in one place 
  and move the crops needing watering to the sprinkler as they become 'thirsty'.
  This way you only need one and you save space!