Traditionally I have run mostly homebrew adventures. I’ve used encounters taken from commercial adventures every once in a while. The Dragonlance campaign I’m running is the first I’ve really tried to run a module straight.
My players aren’t always going along with that idea but that’s ok. I’ve also added some content because I wanted a special event for the character with divine powers. I plan to do the same for the knight. Due to this I created Dulsi’s Dragonlance Addendum on DMs Guild.
For Spelljammer I found the process less satisfying. I had to tweak many individual encounters to match what I wanted. So running it requires looking at the adventure and looking my notes for things to override.
I just ran a Dragon Heist campaign, but I used the Alexandrian remix of it because it seemed interesting. Even then, I added some stuff I thought it needed and removed some stuff my players wouldn’t have been interested in. The ghost in Trollskull was nothing but a piece of set-dressing, as I knew they didn’t want to make a tavern.