Great question. It is very difficult especially on flowering plants but around my house dog hair is a condiment. I have a separate room now and keep everything in there now and the dogs out
Obviously keef would be too small for this, but if anyone comes to this post looking for help with hair in bigger items, there is always the option to fasten a paper towel over a vacuum extension.
Once it's secure with like a rubber band or something and you turn the machine on, it will suck up everything and filter the tiny particles through to the vacuum, leaving what remains clinging on to the paper towel.
Definitely worth a shot if it's something small! Unfortunately keef is too small though.
As for that issue in particular: You could always resort to tweezing! Lots, and lots, of tweezing...