When you see a freighter, burn to it, give it tactical team and TSS. At first, they are all targeting the freighter. But once you open fire, most will switch to you leaving only one or two still firing at the frieghter. Once those one or two are dead, finish the rest at your leisure.
I do this in an Advanced Escort with 2x Scatter volley and Torpedo Spread.
Science ships can use Grav well and cruisers can use FAW to grab attention.
There, now you can run around and solo freighters. No need for extends or baby-sitting. If you do that, you are a wasting damage potential. In pugs, my average is 16 freighters.
For blockade I took one of my spare oddies (The Tac one) and used its universal Lt. Cmdr slot for a sci with Grav Well. I filled the rest with Hazards, Extend Shileds, the 3 teams, transfer shields, and aux to SIF.
I fly in minus the saucer, fire off the grav well, give all the buffs to the transport and then begin firing at will to tank all the damage.
Its my "rescue ship" just for the blockade mission, and I built it out of spare weapons and consoles.
Its awesome seeing just one cruiser escort the transport.
My Romulan Liberated Borg character made it to Level 30 and beat the (old) Defense of New Romulus with the skill point bug.