A few tips. Most of this is more about master mode than expert mode though:
If you are going to continue using the worm scarf, there is something you should know about damage reduction. When using multiple damage reduction effects, some of them are additive on how much damage they reduce. For example endurance potion reduces 10% of the damage before it was reduced from worm scarf, not after.
I think you should at least use endurance potions if you are going to keep using the scarf. You get more value out of worm scarf when using it with the following items:
- Endurance Potions: 10%
- Frozen Turtle Shell: 25%
- Chlorophyte Melee Set Bonus: 5%
- Turtle Armor Set Bonus: 15%
- Solar Armor Set Bonus: 12%
Damage reduction effects work best when you have high defense, and don't work well when incoming damage is much higher than your defense.
I very strongly suggest always using amphibian boots with one other frog leg accessory at all times. When you combine them you get roughly double the jump velocity. Without the ascent speed increase, it will become extremely hard or impossible to dodge some enemy attacks. Queen bee in particular lunges at you extremely fast. I did a Master mode for the worthy run and I was not able to reliably avoid boss attacks without them. You can wear the amphibian boots with a faster set of boots and if you order them correctly you will get the run speed from the faster boots. Extra ascent speed would be useful for dodging the rapid fire lasers from the wall of flesh. Amphibian boots no longer stack with frog legs in version 1.4.2. You might want to use a single frog leg item though.
If you
keep the slime mount equipped, you can turn it on quickly if you are about to fall on an enemy to
bounce off of an enemy's head instead of taking damage. The slime mount allows you to fall faster than normal gravity which can also help you dodge attacks. I would try to turn it off quickly after bouncing because the slime mount has a slow horizontal speed and won't allow you to dash. If nothing else, the slime mount will get you down a hell-elevator more quickly and safely.
If you are going to be using bees, you probably should get a shark tooth necklace. Preferably both shark tooth necklace and stinger necklace. These will greatly increase bee damage against enemies with 10 or more defense.
Using hunter potions during boss battles help you spot enemies that might not do much damage but if they hit you, you might get thrown right into a boss attack. In particular it will help you not have your day ruined by a sneaky floating eye when fighting the mechanical bosses.