- You can get a 380 ghost for 75 marks from the vanguard vendor. This is the most cost-efficient way to spend your marks early on, especially given that you can share it between characters.
- Blues will decrypt up to 385, so don't start decrypting purples until you've hit 385 in most or all of your slots. NB: Ghosts never drop from engrams, so this will probably be trailing until you get a lucky ghost from a Vanguard or Faction reputation reward.
- The first gold-rank public event that you complete per day, per character, will grant 15 legendary marks and a purple engram. There's also a small chance more stuff will also drop. This is a good way to accumulate marks quickly in a single-player activity regardless of light level. You can even do this for the old level 4 public events in the cosmodrome.
- http://destinypublicevents.com/ takes the guesswork/randomness out of encountering a public event.
- The timers aren't super accurate. I think the timers actually refer to the middle of the spawn window for the event, and in my experience the events will typically spawn in the back half of the window, e.g. when the timer says -5 minutes.
- You can trade a purple class-item engram to Variks at the Reef for a 380 class item. These class items are also typically very high stats, but you can use Tower+ to find out the stat rolls on all (semi-)static items provided by vendors, to find the one you want most.
This technique is as old as Destiny, but it's repeated here in case anyone is out of the loop.
Aside from static purchases from vendors, the light level of all gear that you acquire is determined by your character's current average light level, +/- a few (5?), possibly capped by the source of the gear
- Blue engrams currently are capped at 385
- I think purple engrams might be capped at 390
- Old year 1 and year 2 content that drop items directly (raids, prison of elders, etc.) will have their gear capped at whatever was appropriate for when that content was new.
Therefore, when decrypting a big stack of engrams:
- Prioritize the gear slot with the lowest-light equipment
- Prioritize blues
- After every decryption, check to see if the light level on the newly-decrypted piece is higher than what you used to have. If it is, immediately equip it.
- Repeat until you run out of engrams.
Companion apps like Ishtar Commander are great for this
- farming mode that'll automatically move engrams to your vault as you play
- gather-engrams mode that will move engrams from vault to current character
- function to maximize your light level, so you don't have to worry about remembering which gear is currently your maximum light before starting a decryption spree
Probably best to leave any exotic engrams you get in the vault until you're near 400 LL, or you'll be spending a lot of exotic shards to gradually infuse anything you do decrypt.
With that said, a good way to farm exotic shards:
- If you don't have any exotic shards, disassemble an exotic you already have, or buy a shard from Xur on Xursday.
- Go to the exotic weapons kiosk (on the wall to the right, immediately after you've passed the last entrance to the vanguard table)
- Grab the heavy exotic weapon of choice (since they require the least XP to level up)
- Optional: equip a class item that has an XP bonus for the item class you have. (NB: this is the same bonus as consuming a heavy telemetry, and does not stack)
- Equip the exotic while you do patrols, and before handing in bounties
- Once the exotic has full XP, disassemble it - you'll get two exotic shards. You do not need to spend materials to actually upgrade the weapon. It just needs full XP.