Within normal temperatures and other conditions, most can and do do well on weekly feedings. If you're going on vacation, leave them alone.
For almost all varieties kept, an occasional (weekly or so) perfusion (wash?) of live brine shrimp, prepared mash of frozen or dried food, or frappe' (as in with your blender) of "fresh" marine food meant for human consumption (shellfish, shrimp, langouste, not-so-oily fish) with or without supplementation. Temporarily turn off your particulate filters and squirt the food onto their tentacular surface.
Some authors suggest the use of beef and other foods unlikely to be encountered in the wild. I do not.