The bosses aren't difficult if you spend the time preparing properly. Using the Hoe and a few stacks of stone near the summoning area to raise walls to provide you with cover from their attacks and minions or other npc's helps immensely in my experience. I try to raise 4 short walls about 8 meter long and 2 - 4 meter high and thick, gives me high ground against small mobs and decent protection from most boss AoE and Cone attacks. I also make sure to level my weapon skills leisurely as I gather materials enough for several satellite homes in which to protect a Portal near enough the boss to allow for quick corpse recovery should things go sideways and yet far away enough to avoid boss damage.