The Farmer character starts with +30 Harvest, which is also increased by an additional 5% at the end of each wave, resulting in a total of 10% increased harvest after each wave.
However, the character also drops -50% materials.
It almost pushes us to focus on harvesting to get a decent income of materials.
The run is started with the Torch.
If possible, try to get even more harvest at the beginning of each leveling up of your character, since this value will add up extremely quickly due to the value received at the beginning, and you will not feel the less dropped materials.
Get more torches, or other elemental weapons, like the Wand to get free elemental damage from the elemental weapons bonus.
While you deal damage with your weapons, this isn't your main source of damage, and you can absolutely ignore both melee and ranged damage and reduce them in favor of elemental damage.
Additionally, avoid items like the "Scared Sausage", which at first glance seems made for this build, but the burn damage does not stack!
It would just give your attacks a chance (or guarantee for 4 of these items) that you would deal incendiary damage, but since you are already guaranteed to do that with your elemental weapons it would be a wasted item as that damage is always is lower than that of your elemental weapons.
Outside elemental weapons, however, the Scared Sausage is a very useful item, just not for this build.
One item that again works extremely well with the build is the "Snake"
With this item, the fire you cause will spread to nearby enemies, making wave control even more enjoyable and causing you to deal much more damage to surrounding enemies.
Defensively just focus on Max HP, HP Regeneration, Life Steal and Armor and you will be absolutely fine.
After a successful run, you will unlock the "Wheat" item for your further runs.