You can't buy a house without furnishing it, and in New World, the process of doing so is entirely on your back. So, with the wisdom of one Reddit thread and the discussion in it, here is some advice for the mentioned grind.
Leveling furnishing is the worst grind in this game. That being said, here is a compilation of some easy routes to get into tier 2 furnishings, brought to us via Reddit discussions, which has become much cheaper now due to the increased drop rate of refining items.
Round Sunny Rug is one of the better pieces to start with as the requirements are low due to not needing wood/metal. You should craft this up to level 55 or 56.
As with the rug, the Tree Stump Side Table is ideal as it only requires wood, cutting out the requirement to find a tonne of metal which all other pieces this level requires. Requirements for the Tree Stump Side Table are finding or buying the 'Schematic: Stump Stool'.
It is possible that the Cherry Sheets Bunk Bed could be a bug, as this is a tier 2 furnishing that requires iron, rather than steel. This dramatically reduces to cost/grind required to make these pieces. The requirement for this one is the Schematic: Maple Bed 01'. Both of these are meant to take you to the seventy-fifth level.
From this point, the leveling becomes super grindy. There doesn't appear to be an 'easy' piece to craft like the above at the moment. Take note of the economy on your server and grind the expensive stuff and buy the cheap stuff. It's probably the only way to keep your sanity, we are advised.
As for level 100 and further, it looks like incense could be a good way to go, requiring minimal materials but for a lower amount of exp earnt per craft. It entirely depends on how well you can farm/buy cinnamon as this is going to be your bottleneck. Depending on your server, it may be easier than farming iron ore.