Here are a few tips 1. Daily heroic story (highest difficulty will give you two) 2. At least one public event a day (sometimes you'll get lucky and get some shards for doing them, instead of just the post master) 3. Loot chest (lol good luck with that though) 4. Breaking down legendary or higher armor(will give you 2-3) A good way to get extra shards (may take awhile) But If you level three characters to 20 you can get 100 marks for vanguard and crucible each week ... Also do both the daily heroic and public event and put those items in the vault to break down ... You can put inventory items in the vault . So buy your legendary gear each week that you don't need and break it down 5. In conclusion or theory you have the possibly to at least 18 shards a week from buying legendary gear. And you can do the rest of the math