When you write about a boring event, the temptation is to skip that scene entirely, both as a writer an as a reader. Who cares about your character's commute to work, or the mind-numbing lecture on plate tectonics that they attended at the beginning of the novel? If these scenes don't link to the plot or establish your characters in some meaningful way, I recommend cutting the scene and starting somewhere more exciting.
However, if the vital clue to the entire mystery happens best in a boring setting, buried among jargon or gossip...do your best to express the boring scene in an intriguing way. Here are a few ways to accomplish that:
1. Give details about the setting -- Everyone has a friend who will complain at length about an experience. "The conference dragged on for forever! They had us crammed, twenty people in a nine foot by nine foot room, with no windows and no air conditioning. When I got up to use the ladies room, my skirt snagged on the chair. Now it's ruined, and I'm going to bill the conference for it!"
Note: If you don't have a friend like this, your writing may be limited somewhat, but your mental health is probably better.
2. Give details about the other people in the scene -- In the conference example, does the lecturer have a monotone voice, or call on the audience to frequently with trivial questions? Do other attendees feverishly take notes, or do they doze in the back row? Is the cafeteria staff friendly and generous, or mean-spirited and stingy with the portion sizes? This information, even more thean the setting details, will help your reader experience the boring scenes better, because the details about fellow attendees, teachers, waiters, and the occasional interloper will make the experience more relatable.
It will also leave your reader feeling relieved that none of their similar experience have ever been that bad.
3. Give emotional details about your main character -- So, your main character is stuck at this boring conference, with bad food and no AC in the middle of summer in Louisiana. How does your main character deal with that? Is she indifferent, simply putting in the effort because her boss expects her to? Or does she make the best of it, networking with fellow attendees to arrange a pool party after the lectures? Is she angry about being required to attend, or distracted because a family member is having elective but dangerous surgery while she's at the conference?
If it helps, think of the setting details as the bass beat, holding the whole scene together, the other people as harmonies that make the scene more interesting, and your main character's thoughts and emotions as the primary melody that sets the scene's pace and course.
Do all of this, and not only will the boring scene become more interesting, but you may also subconsciously write more hints about later plot points into the scene, like:
A. a poster in the hotel lobby of an entertainer who turns out to be the bad guy,
B. another attendee who comments about the suspicious behavior of the bellhop, or
C. your main character’s emotional state making her choose a different option than she normally would.