The bottom line is that with AI-commanded ships up to ~light cruisers (think Falcon/Fury/&c.) you're not going to avoid losses. Starsector AI is flat-out not good enough to keep flimsier ships alive. It only starts to be reliable with well-armored midline cruisers like the Eagle; even high-tech capitals will occasionally get popped when the AI misjudges the flux war.
Your best bet for minimizing losses while you're faffing about with wolfpacks of frigates, since you're not going to take the most effective route of commanding and killing things yourself, is to reduce risks. Don't go after anything with ships larger than low-tech destroyers, and focus your own fleet around things which are durable (Monitor/Brawler/Centurion) or dangerous (Hyperion/Wolf/Tempest/Lasher). Get through the frigate phase as fast as possible -- normally I'd suggest a cruiser purchase ASAP to give you a flagship that'd allow you to punch way outside your weight, but a single AI-directed cruiser is going to die fast. Instead, repeat the process with durable/hard-hitting destroyers until you have 3-4 of those, then start acquiring cruisers.
The skill combo of Officer Management + Field Repairs for you and Damage Control/Reliability Engineering + Impact Mitigation on your officers is going to help a lot in the long run, but you're still going to take losses frequently even with the best possible AI personalities and doctrines that others have already outlined coupled with durability cap fleets.