Section 1: Handling
Each ship handles differently in different situations,while the Ambassador class is well armored I would definetly not recommend using it for quick strike manoeuvers, just the opposite is true with the Akira Class,it's a well armored class vessel even with the new regenerative shields,but I would recommend using it as a quick strike craft rather than staying and going toe to toe with two Romulan Warbirds.Each ship has their strengths and weaknesses, in order to fight effectively you must learn what these are.
Section 2: Evasive Manoeuvers
Every command officer should know these tactics.These tactics could be those few moments your chief engineer needs to get your phasers online again.A common tactic is to run from the enemy in a zig-zag pattern, I find this highly ineffective,it shows the commander of that ship thinks on a 2D level and has trouble adapting to new environments.You have 3 Dimensions to use, be creative and try new tactics, some might not work, some will work,but they will help you adapt in combat.
Section 3: Combat
Most ships can hold their own for short times in combat,the larger classes such as the sovereign are designed to be a mix of speed and durability.For the smaller ships I recommend hit and run tactics,target the Sensor Array to begin with, this will render them almost blind,after the sensors go after the impulse engines, keep the phasers set to full intensity when doing this, you aren't looking to damage these systems, you want them destroyed.Don't worry about the shields, they'll collapse in time.Now to make combat even quicker focus all your fire power on one key system,no not the shield generator,try the warp core or power plant,once this goes the ships will loose containtment and explode.Another tactic I use is close the distance (14km or so) and then activate the tractor beam,if your opponent can't move they can't fight aswell as they could with full maneouverability.