After scouting out the immediate neighboring stars to make sure I even have the luxury to think about exploring (as opposed to fighting a war of survival on my doorstep), I go to a fleet-based exploration model with a 60k-ton carrier as a command ship for an exploration task force, which will travel with a tanker and several corvette-sized escort ships. The big 60k-ton command ship has fifteen FAC-sized survey ships in its hangars, 10 for geo scans and 5 for grav scans.
When exploring a new system, at first the escorts peek in (the carrier doubles as jump tender), and if there's no sign of trouble after an hour (ie, a hostile fleet camping the other side), the carrier and tanker follow. They all wait at the entry jump point for another week and if nobody seems to be home (ie, no long-range missile fire, no scouts showing up to investigate what the heck just showed up in their system, and no giant thermal/EM signatures coming from terrestrial planets), I give the all-clear for the parasite surveyors to go out and play, scan all the things, then come back to the carrier.
While it might have a little bit of fight in it, the carrier wasn't made for serious combat, never leaves the jump point, and in the event that something hostile shows up that got missed, it'll just jump right back out along with the tanker while the escorts cause a distraction. The little surveyors are expendable. If they make it to the jump point, the carrier is waiting on the other side holding the door open, and the escorts will do their best to fight off anything unwanted that follows them. If they don't escape, oh well.
Then it's time to send in the bigger guns.