My father owns a gym, I work there as a personal trainer and, what do you English cunts call it, "weight room assistant"?
Basically I mostly show people how to do things properly and spot them.
The best spotter I've ever seen is easily myself, seems like very few people understand how you're fucking supposed to do it.
I'll give y'all a quick guide on how to spot, since most of you are daft anyway.
Let's take the basic example, bench press.
First, you ask them how many reps they aiming for. That helps you know how much you should "interfere".
Second, you don't even help them unrack the weight unless they ask you to. It can easily throw off someone's concentration if they're not used to it and get surprised or weirded out.
Then, on the first reps, keep your fucking hands to your sides, 99% of the people aren't gonna fail on the first rep. Exception to that are people going for heavy singles, doubles or triples, in which case your hands should basically hover the barbell by a few millimeters without actually touching unless needed.
When the guy starts to fail, you use your index fingers to give him the slightest boost. Sometimes, even just touching the barbell with your fingertips takes enough weight off him that he can finish the rep(s). If he has more and starts failing badly, that's when you close your hands around the bar and give him a stronger boost.
The key here is knowing just how much force to exert, so the guy being spotted can still bust his ass completing the set without the bar crushing him or you doing all the work.
Nothing makes me more livid than a spotter that does the work for me, I hate wasted sets.
I often get compliments, even from people who have been training for more than a decade, on how good a spotter I am. Initially I tought it was common knowledge, but I changed my mind when I saw how bad peiple are at spotting, even the aforementioned guys with 10+ years of lifting experience.
Tl;dr learn to spot, it saves lives and workouts