Mistlands is annoying to me due to the mist mechanic being too oppressive even with Wisp Light, Wisp Torches or Mistwalker weapon. That and the terrain is very stop and go due to how jagged it is, having to jump a lot and having an extreme cut into water resulting in less then dependable shorelines.

Exploring wise I used padded helm/leggings and root chest piece (pierce resistance is great against seekers and dverger rangers) and carried materials for workbench, stone cutter and a portal for when I find either a dungeon or a dverger tower that I would dismantle for materials (having wood for a chest can be good as well).

Weapon I just used Frostner and didn't really bother with the shield since with timing and the special attack + slow it's pretty easy to handle a lot of the Mistland enemies. Iron Sledge is good for cheesing enemies via ledges or killing ticks. Drauger bow for those enemies you can get away with killing from a distance or you do not want to fight a certain enemy (like a 1 star soldier in the mines).

Beyond that make sure you have decent food and potions. Mead can be really good for gaining back stamina quickly while having zero cooldown though you can't make use of it while running but instead walking / staying in one spot. Fire resist / cold resist potions can be nice against the Gjall or Dverger mages - sometimes I'd have a stack of fires but not cold.

When moving around I find it best to try and reserve a bit of stamina just in case I need it and move around rather slowly because of the mist. Use the map to mark locations or points of interest like dverger forts, docks, ruins, bridges, giant armor, giant sword, petrified bone, and petrified skulls. Map use can be extremely helpful.

edit: I finished solo via cheesing the Mistland boss as I was rather annoyed with how the new biome was designed. Built a base in plains outside of a mistland location and tried to never land my boat on mistland shores except one time to explore a dverger fort that was on an island. Better to land in a safer biome and set up a safeish portal and then portal around when exploring inside.