[Blaster]

As the above says, is there an easier way? I've seen people with over 800K and I dunno if they just grinded for years or if theres a quick way.

[Jestersmith]

Run random tfo for the choice box to build marks and dil up with he marks to build a pool in all reps then if you have multiple toons run your daily hourly reps on all even when reps are maxed to t6 this gives you 4420 for all 13 reps hourly set it as you get on the game and get off and you hit your daily 8k with just that then do the fleet research lab daily this gives 1200 dil daily

Some good pointers on this video for you also

[Taku]

To build up your reserve of DIL ore, do Ferengi Alliance Admiralty Missions and run regular missions.
To get to 800k refined DIL you have to either grind it out at 9,000/day (for lifers) or buy it with Zen.

You're either grinding for months or spending cash. Right now DIL is trading at 474/Zen. To get to 800k DIL, you would have to spend 1,688 Zen. That would cost $20.

[Solace]

A good source of dilithium is running the daily event TFO once you have completed the 14 days needed to get the reward. Aside from that as Jester said random TFOs are your best bet.

For big chunks of ore you can turn in any spare rep marks and elite rep marks for some dil. I do that on occasion, 3000 omega marks netted me around 40,000 ore. Its a tedious process for sure but the gains are pretty good.

Other than that you can convert zen into dil on the dil exchange it was 491 last I checked.

[darthnovawave]

I usually just run random TFOs. I don't really need rep marks right now on most of my endgame toons, so I keep a stash of about 500 marks and 5 elite marks for rainy day shopping, then convert the rest. You get 500 dil for every 50 regular marks plus 1000 dil for 3 elite marks. Doing this I can hit 8k dil usually after 3 or 4 runs. The only downside is with randoms you may get ISA and other Borg space runs that only take a couple of minutes...or you may get the Vault or something that drags on forever. Admiralty is a good choice too, but it isn't the most engaging gameplay.

[Draco]

Didn't see it mentioned yet - but buy (or farm) contraband, daily mission to turn it in at a security officer for 2k dil.

After you max out specialization points, every time you gain a 'level' you get some dil too. What with Ferengi admirality (30k bonus pool every time you complete), dil from endeavor boxes and the occasional reward from patrols and things like Dyson sphere ground (when grinding damage or kill endeavors), I seem to average more a day than what I can refine on my main toon. Unrefined is sitting at more than a million and keeps slowly increasing.