Equipment - Equipment is really variable and relies on the luck factor of the player since some of the better equipment are randomly found and sometimes, even, your world may not even have one to begin with. So a general tip is be the best you can be at the moment. If you find the highest ores such as Gold / Platinum, make your armor out of them. Not just your armor, weapons and tools as well. It may take some time farming for ores, but while farming for the ores, you may run into weapons that may drop from enemies and / or are in chests.
Quick Tip: Ranged weapons are highly advantageous and keeps you safe albeit at the cost of some ammunition. A Golden or Platinum bow is recommended for most boss fights.