Wrathamon
Adventurer
A good mash-ups are more for TV style story driven type adventures imo (not sandbox, but not to say you couldnt, but sandbox can have many adventures that arent connected).
One adventure is the Meta plot of the tv show with the other adventure(or adventures) as the primary plot of that episode.
Other, I have done a lot is the Twist or weave style. You weave two adventures together as plots of one pop up you weave the player into the other story arc or the players weave themselves towards which hooks present themselves more enticing. As one story arc ends the other starts to climax and you weave the next story arc in or end with a bang. The adventures arent run sequentially.
I did these with some of the published Eberron adventures and the RPGA adventures with new encounters\story moments to bridge them together. It worked really well and was probably one of the longer running campaigns I had during 3.5.
One adventure is the Meta plot of the tv show with the other adventure(or adventures) as the primary plot of that episode.
Other, I have done a lot is the Twist or weave style. You weave two adventures together as plots of one pop up you weave the player into the other story arc or the players weave themselves towards which hooks present themselves more enticing. As one story arc ends the other starts to climax and you weave the next story arc in or end with a bang. The adventures arent run sequentially.
I did these with some of the published Eberron adventures and the RPGA adventures with new encounters\story moments to bridge them together. It worked really well and was probably one of the longer running campaigns I had during 3.5.