So I don't have the prep time I did back in the day. This can make running games a bit tougher than it used to be. To that end, I've come to enjoy modules more and more these days. I've got quite the collection of B/X and LL modules and eagerly add to it on a regular basis.
I always like to open my Labyrinth Lord games with the module Larm. It's a good sandbox adventure with a handful of mini-quests that aren't too deadly for first level PCs. As I thought about how to build on it, I thought of a few other low-level modules I own that I might seed within spitting distance of the village. After some thought I decided to also add Hall of the Mountain King to the rumors and hints around the village of Larm. It'll give the PCs a solid dungeon crawl. I can even tie it to the goblin camp bothering the village by saying they're lead by the mysterious "Mountain King" to create a multi-layered experience.
So now my players spend a few levels running around the village running errands. While they're away on one of these errands, I can tell them that several NPCs arrived in the village while they were off being heroes. One of these is a group of travelers going down the Dolm River to Dolmvay. This allows me to use Dolm River. Another of these NPCs is going to pick up and escort someone back to the city of Dolmvay from a keep far out in the wilderness. This keep is, of course the Keep on the Borderlands. After helping the Keep they PCs can escort the NPCs back to Dolmvay, but learn of their secret past via Kingmaker.
Once they arrive in Dolmvay, they can find assignments from the Adventurer's Guild - which will actively attempt to recruit them, having heard of their exploits in the adventures listed above. Perhaps they get tasked to investigate the events surround Oak Grove Whispers. Or maybe the Church of Law and Order heard how soundly they dealt temple in Larm, and asks them to investigate the Shrine of St. Aleena. Along the way to any of the adventures mentioned above, they might end up staying for a rather troublesome night at the Inn of Lost Heroes.
Holy crap. I think I just organized three months of a campaign with almost no effort. Go me.