All machines on the Island Farm can be upgraded with Mastery points. Mastery points are indicated by blue stars on each machine. The more stars you obtain, the more items you unlock. Tapping any machine on the Island farm will display a pop-up screen with the number of blue stars you currently have (see image below):

Every time you create a product with a particular machine on the Island Farm, you will get Mastery points. These Mastery points will only be counted for the same type of machine. For example, if you need to produce Wool Cloth with the Loom, the Mastery points you get from producing it will only count for all the Looms you have on the Island Farm.

If you want to know how many points you need to unlock the next Mastery level, tap the question button next to the blue stars (see image below):

Then you will see how many points you need for the next star, as shown below:

Use the special Circus Monkey boost to get more Mastery points. For more information check 'Game Tips Seaside Farm' -> 'Circus Monkey'.