Move forward more slowly, so you don't aggro huge groups. Fight things one at a time if at all possible.

Use the stagbreaker or atgeir, for AoE attacks with knockback.

Use the hoe to level ground, so you don't have to slog through deep water. This also helps avoid leeches.

Stay out of the swamp at night; the cold and wet debuffs both nerf your stamina regen... and they stack.