Key thing here is patience and what item it is, if its item that has steady consumer base you just wait price spike and sell them then. It might take days or even weeks depending how "hot" that stuff is. Or if its craft material and you have a crafter you can turn those to complete product and sell them instead, but to make all this work you need to know how your realms market works so you can minimize all risks.
But then again i have always treated money making in MMO's as an mini-game so i always try to maximize profits, if i cant get insanely ludicrous price out of item i wont bother to sell them at all.
HQ Brass Ring = 20k each while it costs less than 200gil to make one... good times :3
