This is a companion post to this one I posted yesterday: https://www.reddit.com/r/WaterdeepDragonHeist/comments/hq4yge/some_of_my_favorite_moments_so_far/

As a first-time DM, I've definitely made a few mistakes and missed a few opportunities to make the campaign more fun for the adventures (spoilers ahead):

• During The Yawning Portal bar fight, two of the characters ran to get the City Watch. This wasn't something I had expected but makes complete sense in hindsight. On the fly, I told them that it would take at least a few minutes to track down the City Watch and bring them back to the bar. By the time they came back, the fight was over. I also had the City Watch take over the scene, pulling Yagra away from the PCs. I feel like the players didn't get much from the fight.
• I completely forgot to include the dozen dead bodies in the description of the interior of the Zhent warehouse. I was so focused on figuring out whether or not the kenku were going to surprise the party. The session ended right as the party had finished off the last standing kenku (one kenku was asleep), so I sort of shoehorned the dozen bodies in the description after the battle ended at the start of the next session--saying they only noticed the half-hidden bodies in the dimly-lit warehouse after the battle ended.
• I might have made the stolen goods in the Zhent warehouse too hard to fine. The party became convinced there was SOMETHING of value in the warehouse after I told them they noticed bells above each of the office doors. They rolled high investigation checks on the north wall to the east of the stairs on the first floor, but rolled low for a search of the north wall west of the stairs, where the secret door is. I wonder now if I should have made the first successful check for the whole north wall or entire first floor.
• While the PCs were searching for the sewer entrance in pursuit of Floon's abductors, I might have goofed twice. First, one of the players thought to track down someone from the Dungsweepers Guild to learn more about the sewer. At the moment, I had struggled to think of a way to make tracking down one of the 'sweepers an interesting interaction. They asked an innkeeper and bribed her, but it was only one silver piece so I told them she didn't have much info to offer. Then, when they went to the streets to search for sewer access, one of them rolled high for an investigation check. The problem is that I didn't say they had found signs or evidence of Floon's abduction. I just said they found a sewer entrance, and then they found the yellow chalk sign after entering the sewer. It now feels like I railroaded them and skipped over some details.