I'm not the greatest of modellers, but over the years I have, through actual trial and error figured out that some things work and some things simply don't. Yet I see people who use modelling practices that defy all reason, make your life more difficult and often don't work at all.
I happened to watch a demo a while ago and the guy was trying to explain why you should use tweezers rather than fingers to apply decals, while using fingers is a less than optimal method, tweezers don't quite work …
Using tweezers for decals is the same kind of nonsense as trying to cut parts from the sprue with a knife. I suspect it is some kind of affectation people pick up from other people and never bother to actually verify.
I use a brush to handle decals and it works much easer than trying to stab tweezers underneath the decal, praying you won't damage it or that it will not fold on itself, gently use the brush to slide the decal off the paper and a properly sized brush has a large enough area to prevent most decals from folding. The advantage with the brush is that you can make corrections without having to stab and peal away with tweezers at the decal, risking damaged paintwork.
Same with cutting parts from the sprue, people always tell me that I damage the pieces with my flush cutters, I can count the number of parts I broke over the years on the fingers of one hand, half were damaged and weakened on the sprue before I cut them, others were parts so small it was beyond reason to try to cut them by another method than very careful sawing. The rest were due to it being a crappy model to begin with.
Yet the knife and scalpel crew break two or three parts per sprue and it's always the same excuse "Oh, but the knife isn't sharp enough." I never had to sharpen my cutters even once, they cut just as well as the day I bought them (I did buy quality ones)
And then there is always that part that gets away because you need to put a sprue down and cut with a knife in such a way that the part is likely to bounce, yet they seem to believe the sprue is some kind of invisible force field that will prevent the part from escaping.
They claim it almost never happens, if by almost never you mean the three times per hour on average that they suddenly disappear underneath the table for fifteen minutes of frantic searching.
When I cut, I look for the most favourable angle and hold the part with two fingers before I cut or make sure it will at least fly off in a predictable direction. Yes, some parts I cut need a bit of trimming, but at least I'm not trying to glue two parts of an antenna back together and fight a losing battle against keeping it as straight as possible.
And I'm not going to start with the people who use glue in homoeopathic amounts, because less than a single molecule of glue is an infinitely better bond than any reasonable amount of glue. The whole "you need to dilute your glue and use a toothpick to apply microscopic dots" doesn't work for any two parts that are larger than two grains of sand.
Some models put a huge amount of stress on parts and yet I see people apply the mantra and then weirdly believe they used too much glue when the model splits in half. Sorry people, glue only works if you properly cover the entire two connecting surface areas, you don't need to drown them like some people on the other end of the scale do, but you need to apply an even coat, and the real trick is to keep the glue the right thickness, especially with brittle glues that are not very resistant to lateral forces. The problem is that I see too many people apply nothing more than a mere mist of plastic cement, anything more brings on a "too much glue" panic attack.
Because they use so little glue the model has to be kept together with tape, hope, prayers, and clamps right until it has to be painted and they have to make elaborate constructs to prevent the modelling equivalent of a house of cards from collapsing as soon as a drop of paint touches it.
"It's a model, it's supposed to be fragile." No, it's not, I can pick up any aircraft in my collection by a wing and it will not disintegrate. (Yes, there are models that no amount of glue will prevent from losing a wing if you hold it that way, so no need to pick up that point)
Next you have the "Superglue conquers all" crowd. Superglue is the best glue in the universe, period. Nothing does the job better, except that after two years that model that started off as rock-solid is shedding individual parts at an alarming rate and more and more amounts of superglue is the only answer. Yes Suzanna, there is a specific glue for every job and superglue is not a one size fits all solution, some day people will learn to acknowledge it or die screaming in a padded cell.
And then finally there is the rare category of "Why use a knife or flush cutters if you can use a $1,500 USD miniature table saw, a $15,000 USD hydraulic pressure cutting tool or a $250,000 USD CAD all-angle cutting laser to assemble an Airfix Spitfire." I make models for fun, not as a justification for existing.