But ,

use the method that works best for each part .

Sometimes slicing the part clean off the sprue is the best route depending on it's size / geometry / location on the sprue .

I got into the habit of roughly chopping out all the parts necessary for completing a particular step in the instructions and placing them into a container or a pile  and then cleaning each piece just prior to inserting them into that assembly.

Just make sure you have a system to keep similar looking parts separated ( like left / right components ) so they don't get confused off the sprue .

Like a left , right container ( obviously  )  or just a small slice of masking tape stuck to whatever part you need to keep tabs on .