I usually just rank in the common high exp areas (calandryl, kiadana, spirits, headhunters, etc.).

I generally expect company when a potential enemy is logged on, and make sure my groupmates can hit that potential enemy, as well. Sometimes I get cocky, misjudge the danger and get smoked. Sometimes the enemy comes and gets smoked. Sometimes the enemy comes and I take off for a few hours until the enemy leaves and then return. But overall there do not seem to be very many people aggressive enough to check all the ranking spots over and over and over to hit a group of three, and skilled enough to pull it off. So my advice is to just wait out the skilled hyperaggressive ones, or make sure you can drive off/PK the skilled hyperaggressive ones.

However, getting to 51 isn't as much of a priority for me as getting into PK range with hero characters. So once I hit 47 (or 48 with a warrior) there's not much incentive to race to 51.