Many DMs have heard the complaint over the years: “You’re railroading!” If you aren’t familiar with the term, it’s the behavior of a storyteller forcing the players to make certain choices. This can be accurate, or just a misinterpretation of a player who feels they get little decision making power in the group.
A creative DM can fly by the seat of his/her pants long enough to bring things back around in a natural way. If a player decides to help the farmer for free rather than go on the lucrative rescue-the-princess quest, maybe something comes up with the farmer that prompts players to pursue the princess, or whatever. Other DMs just go with the flow, and let the story grow with the telling, rather than following a defined story arc.
But what does a DM do to prove they aren’t railroading players? Chessex dice provide a nice option: Dungeoneering Dice. These dice have randomized choices for your dungeon, which can help you raise suspense for your players. If your players (or you) draw your map as you go (which you should), you can correct any oddities by adding stairs. If your players take too many turns back on themselves, and find a door running into what was previously a hall with no exits, then they are above/below it now!
Always feel free to innovate. That little change can make a lot of games more fun.