Enemies seem to fire at whomever is doing the most damage to them, if no one is shooting them, they pick the nearest threat. A good way to draw aggro is to shoot EVERYTHING. Beam fire at will helps with this.
I tend to go for the increased regen ability shields, Seems to allow me to shrug off more damage then without it.
I also use for my BOFFs....
Ens Tactical: Undecided at this time, currently Beam Overload
Ens Engineering: Engineering Team 1
LT Engineering: Emergency Power to Shields 1 and 2
Ens Science: Science Team 1
This allows me to sustain broadside attacks much longer, especially with redirecting shield recharge to the facing shield....which I don't do generally solo...as most of the time, I am the only target....
Oh...and I tend to keep a supply of weapons batteries....so I can immediately unload on a target after dropping from Full Impulse.
Theres no starship tanking in the traditional sense. The most useful cruiser captains I've teamed with play it out like DnD clerics: throwing buffs and heals around while engaging the most heavily armed ships in the mob, while the rest of team takes out the smaller ones first. Healing and buffing actually does seem to draw aggro a lot, based on what I've seen. Bad news is that just like most of the game, the team window is frikking bugged and doesn't show all teammates shield status, so communication is key.