Jodie - trimming them for a dog show? I would hope that would still be optional (maybe start with taking off the larger "walrus" ones?) If you want the clean look, I'd start by snipping each whisker one at a time with short blunt ended scissors. Work the scissor down to the base of the whisker hair. Some folks use long straight scissors and work from the back of the head towards the nose and scissor them off in groups. Since you are doing it for the 1st time, the group route might be risky since you could cut off muzzle hair too. If your dog is settled and calm, sit 'em on a grooming table and snip away. You might practice on one of your other dogs first if this is for an upcoming show.
When I trim whiskers, generally to make a wider muzzle look more slender, etc., I do it like GoldensInRI, one at a time. I do it in small bits if the dog gets antcy. Is there a particular reason you are trimming them off?
Sneezing during heeling. I posted some video of him on a facebook group with some pretty experienced trainers, and sneezing due to stress has pretty much been eliminated. So more likely options decided upon are sneezing just because of the thrill of heeling (yeah he thinks everything is a blast except stays), nasal drainage due to lifting the head, or Ward Faulkner (who just won the National Obedience Invitational btw) said his dog sneezed due to whiskers brushing up on his pants and it stopped once he trimmed them. Petra Ford (who won the NOI twice) said I should try it. So, I figure, Ward and Petra said to trim whiskers, I'm gonna trim whiskers! LOL