1) Fart and walk around to spread the smell.

I've done this many different times and I believe it is the best way to conceal any fart whether big or small. This technique won't really work if your farts are loud but if they are silent and deadly like mine this works almost every single time. If you left a friend's conversation or see your friends while walking try and walk a extra 4-5 minutes to complete your innocence.
2) Go to the Bathroom

This technique also works wonders for me and I think that not many people do this. Sometimes when I'm walking, and I feel a fart coming on, I dash into the closest bathroom and release my pent-up fart. I also suggest going into a stall because if you fart loud in a stall people will just assume you're just going number two and there also isn't too much embarrassment since people can't really see you either.
3) Yell something loud

I've used this maybe once or twice but it does sort of get the job done. This definitely won't work if your farts are smelly but if they are just loud with no smell I highly suggest this. You can't yell something on the street randomly but if you're in a conversation with one of your friends and you feel it coming out you can just yell something like WOW THAT'S SO INTERESTING or AWESOME (it has to be enthusiastic and related to your conversation). The key thing with this is you have to time it just right with your fart. Sometimes, people fart before or after they yell and then it just defeats the whole technique.
4) Blame someone else

This works only if you are great actor or actress and you can clearly communicate with people. You can't just blame someone right away for that smell you already knew was coming. I wait a couple of seconds until someone else has smelled or heard that someone has farted and then I immediately go to work. I have a long story in mind and use my excellent "detective" skills to find that some other person farted when I usually am the one to blame. Be careful ,though, never do this with just three people because usually they can figure out it was you.
5) Pretend to be clueless

In meetings or classrooms if you let a fart out and you just pretend nothing happened sometimes everyone else feels the same way. A great tip to follow, when you're in class, is to put your head down and pretend your are sleeping. No one blames a guy who's asleep for that massive fart in the back of the class. In meetings, I'd just let one rip and keep going about my business because usually everyone else is focused in the meeting too . Even if I'm sitting around with my friends and the blame game is played. I usually just keep out and just keep quiet because even if someone blames me. My friends usually don't do much after that if I act completely oblivious to the fart.