KDF is known for their marauding missions that yield large amounts of contraband which you then turn in for dilithium. This paired with prisoner labor camp missions means you hit your 8k limit with little effort.
I would suggest making one KDF toon, even if you won't play it, just for this.
Fed side I like Beta Ursae for the missions they provide. It has easy access to nearby sectors and typically has lots of mission options in sector and on DS9. If you lack DOFF's in general however stick around academy. The advice of academy--esd--sector block is a great method until your roster is built up.
you can also do this on DS9 (the officer is right outside the bank area) every 4 hours.
Growing old is inevitable. Growing up is optional.