Level up your characters!
Every time you level up your character, you get 15 mastery points.
Every time you unlock your characters, level 10 or 20 costume, you get 25 additional mastery points.
Every time you hit the maximum level on a character you get an additional 125 mastery points.
Increase your profession skills!
Everytime you hit these numbers of skill points, 50, 100, 150, 200, 250, you get 75 mastery points and unlock more things to craft in that profession.
Learn recipes, mobility items, styles, allies or costumes!
To get recipes, do recipe dungeons for one recipe item, these grant you 2 mastery points.
To get mobility items, you have to craft them, buy them or adventure! Most of these grant you 50 mastery, sometimes 25, depending on the rarity.
To get styles just loot collect items for their styles, 1 mastery point per style.
To get allies, adventure on! Or get them through soul-traps, bought from pirates for 300 glim each. Some grant 10, some grant 20, some grant 50 mastery points.
Costumes are usually only bought by adventuring and buying from other players or being bought with credits, they grant 25 mastery or more if they have special helmets or weapons.
Go fishing, common fish unlock 5 mastery points the first time deconstructed.
Uncommon grant 10 mastery points.
Rare grant 25 mastery points.
Fishing poles grant 20 points each.
Sails grant 25-50 points each.
Boats grant 50 points each.