You can increase Irith's mood +5 by bringing her more than 100 gold at once up from the dungeon
Irith's mood drops -5 every day without at least 20 gold brought up
Irith's mood takes a hit if you fail chores or act too inconsiderate during (sex) favours
If her mood drops to < 35 she refuses to talk to you, you can raise it again but for that you need money (see above)
Items & Dungeon
You can get enough money if you convert expensive items like scrolls or even crystals to gold (use a crystal of value to amplify payout)
If you need bombs, use a lamp oil in chest with exchange scroll (30% chance)
If you climb up from dungeon taking gold from the stash instead exploring you have completed your task already at 10:00h and have the day free
If you use a glitter fragrance (can be found with magic chest at random) in the bath (use correct color!) you get 30 FP
If you run into a slime in the dungeon, the Renpy back button can give a new try (no data corruption side effects seen so far, but there might be a risk…),