Well, the Blacktooth Ridge is actually based on a module. At first it was an off-shoot company, but about little over a year ago Wizards of the Coast actually picked it up and published it as a book with some other stuff. I don't have the book, but I have some of the older materials. But that just gave me the setting and the original quest - so the Twins and the Vargolg, for example. Boris was in it as a little side thing but nothing much was mentioned about him. That seemed like a waste to me. 90% of what you have encountered is just me elaborating on what was a very broad base. But I did have something to start with. Plus, as characters always do, you quickly went off script with a full frontal assault on the Vargolg and I had to figure out how a battle would play out.
As a more general statement I would suggest a few things:
1. Don't be afraid of published modules. They are a great way to start out and a lot of experienced DMs use them. They make life a lot easier. Plus, there are still tons of places where you can put in your own embelishments like Boris.
2. If you want to do something on your own I would suggest thinking of a character or a location you like - then see if that inspires anything. I'm a teacher and once a week I run an after-school game for staff members and right now they are on a side adventure that is based around a chracter I first developed on this site. Zebulonicazarius Zickerthorn is a gnome alchemist of extremely high level (ok, on this site, he was just second or third but he's had a successful career in my head) who runs a magic emporium not unlike Weasley's Wizard Wheezes that needs to employ some people to acquire things. Zick is awesome. And a great way to send a group of characters into a nest of hags. Half the times I just think up places or things that would be fun and then go from there.
3. Don't be afraid to get help. This could be asking others such as myself. Or steal maps off line. Or google "Cool Pirate magic items D&D" when looking for something.
4. Characters will do there thing - roll with it. There was nothing in this module about a pyre. But there needed to be some aftermath to the battle. So I just considered what the monsters would likely do. Monsters aren't dumb. They will deal with their dead, but they will also have guards. They will set traps. Much of what happens is the DM going, "Well, that wasn't what I expected . . . so . . .this happens!" I make crap up.
I'd be happy to help in any way I can.