There are many steps to exploring that should be observed before exploring. The rundown for exploring in a way which you are not screwed goes as follows:
-Make two sets of gear, don't skimp on gear. I may not carry every weapon type but i have a couple tucked away somewhere.
-Sailing should be done while only carrying the materials to make a workbench and portal. Food of course for making sure your not lunchmeat on landing. But do not wear your good gear while sailing, also always have a pick capable of scraping barnacles. Other than that, nothing else.
-When you come ashore from sailing, try to land in a meadow if possible. Put down your portal and build a defensive pit around it with your pick. Double trench if you feel a troll or something bigger might wander nearby. The pick and hoe are your friends, you can dig pits and elevate your building site for extra safety.
-Once you got your portal setup with necessary defenses you take the portal back to your main base. This is key here, always have a pairing portal back at your main base. It may seem odd to have a metric ton of portals sitting around but it will save you time. This allows you to get some food in you after a death and put on minimal gear to recover your gear and pop out somewhere and hit the ground running.
-Boss fights are not always fought with your weapons, I personally find the summoning altar and formulate a plan! Remember you can jump but most mobs do not, therefore an earthen wall made by your hoe can be jumped by you after spawning and the boss may not even detect you. It sounds cheesy but if your alone some of these bosses are not kind, therefore most boss fights are fought with a 2 handed hammer after prepping the site for the fight. This works for all the current bosses but moder, moder is her own beast.