If you want to level quickly here's another tip beyond DOffs and the Mirror Incursion.
You should be running Foundry missions, a lot of them are just great stuff that feels a lot like episodes of Trek, good ones, and they're great fun. Also, there is the "Investigate Officer Reports" mission available that gives you 960 Dilithium just for running a Foundry mission.
Now, something else to do at least once a day is run a farming mission. These are exactly what they sound like, a mission with nothing but a bunch of enemy battleships in it to blow up. They are not aggressive and won't attack and have a nebula radiation debuff that keeps them from raising their shields. In other words you blow them up and collect the loot. The most popular is the QWARK series, he has one for below 50 characters and one for 50's. They last long enough to fulfill the requirements for the IOR mission and will wind up coughing up 50 items for you. Fifty items happens to be the daily limit on items from Foundry missions. The benefit when you're leveling is you get the experience for killing a battleship.
To do this first make sure your inventory is mostly clear. Dump whatever you don't have to have on you in the bank. Hit the communicator shaped icon on the lower left of your minimap and look through the available missions for IOR and take it. Then go to the Foundry section and look for the QWARK Farmer mission. It'll likely be near the top if you sort by rating. Accept it and start it. When you do start open first on your first target and drop it to around 50 to 60% before hitting tab to the next undamaged ship and doing the same. Keep going until you've tagged at least ten to fifteen ships in each wave then destroy one. It's explosion will take out the others around it. Collect your loot and go to the next map. Keep it up until you finish.
So now you've got an inventory full of loot, what to do with it all. Well a lot of it is just junk. "Critical Components" allow you to repair your ship if you get destroyed during an elite ranked mission. You can just use EC's to do it at Earth Space Dock. So if you're low on space just vendor those. Batteries and such are up to you how many you want to keep. I just keep a stack of 20 on me and vendor everything else. The farming missions keep me topped off so no point in keeping extras. All white and green level consoles and weapons are vendor junk. They only sell on the exchange for a bit more than vendor price and take up some of your 40 exchange slots. The exception to this are turrets, those can sell for quite a lot, even green ones, and blue consoles or weapons some, SOME sell for quite a bit so it's worth checking. Ship shields, impulse engines, and deflectors can sell for a pretty penny so put them on the exchange. So you're going to vendor probably 3/5 to 4/5 of what you farm up and even the lower level farming missions will spit out probably 125 to 200k EC. Then you can get another few hundred thousand from sucessful sales.
On the exchange it's easy to look up items to price check them. Use the filters to limit things to the right level range. You'll get mostly items for your level so just set the level filter to whatever you are. Then set the rarity. Then go down to the right section of the exchange. Now just grab the item from your inventory and drag it up to the search bar. It'll auto-populate now just hit search. Personally when I farm I usually wind up selling most of the stuff for about 95% of the lowest price. I'll sell most of the stuff I farm up within an hour at most. I don't worry about getting the most for what I'm putting up, I just want to sell it off quick.
So, for about half an hour of work you'll get 960 Dilithium, a level or so from XP, and make about 400k EC. Add in the Mirror incursion every other day and you can be averaging 5 to 6 levels, 2,000 dilithium, and 800k EC every two days. Work like that and you can go from starting out to level cap in two weeks and you'll get there with several million EC in the bank.