I've lost Armageddon and apocalypses in the time it took me to align and get to 75% speed
Complex Running Guide - Complex grinding is about the most profitable thing you can do in EVE right now, it's why every good complex is religiously farmed by WOW Power Leveling somebody, often by many competing entities right after downtime.
Right after server comes up from a reboot/downtime is just about the only time you can be certain it's fully spawned and empty of competitors, (thus) if someone else does show up, you can kill them and claim the complex as your own, or team up / drive them off if you don't have a warp disruptor handy.
Okay, let's take an easy 6/10 sansha complex as our example. None of the NPCs webify or scramble you, just lots of battleships, a few cruisers and frigates; this does not mean its risk free of course.
I've lost Armageddon and apocalypses in the time it took me to align and get to 75% speed required to warp, even tanked ones, as 8+ NPC battleships can dish out a lot of damage if they're within range.
Doing this complex efficiently and profitably requires a minimum of two people; if you're soloing all you can do is grind the first stage for Phantasm BPCs / 11th tier overseer effects, so make friends with someone if you don't have any.