Here's the book I wrote: Most important factor is proper torque. Second most important factor is lube on the spindles (I prefer anti-sieze lubricant).
Torque helps to ensure a proper balance between the crank fixing bolt stretching and developing the tension that holds the crank in place, versus the elastic deformation of the crank's square taper interface that prevents it from riding any further up the spindle. Too loose, and the crank rides up the spindle on its own (under pedaling torque) causing the bolt to lose tension and even allowing it to back out.
Lubricant does nothing more than to preserve the interface by preventing galling of the machined surfaces during the installation process, acting as an anti-corrosion layer between the aluminum crank arm and steel or titanium spindle, provides for consistant forces (as measured by the torque wrench) over the course of repeated installations, and assists in easy crank extraction.
LocTite is unnecessary. Proper torque resulting in sufficient tension should hold the crank fixing bolt in position without any aide from threadlockers.
Shimano specs proper torque at around 35 ft-lbs; other brands are in a similar range. Without a torque wrench, sometimes this feels like "too much", that's you've gone too far and are stripping or damaging something. Fact is, it just takes a long time to build up to full torque, because unlike a normal bolt application where you're fastening against something hard, in the case of a square taper crank installation you are slowly walking the crank interface up the taper, resulting in a prolonged build-up to proper torque.
As an aside, I've been running Octalink for a few years now and the bearings have held up fine. I don't read about many Octalink bearing failures, but the ISIS stuff does seem a bit abundant. Octalink cranks seem even more likely to work loose if not torqued correctly, but once they are fastened up per manufacturer's spec, they stay tight and present no notable problems.