If we are being honest, a one rep max attempt is always guaranteed to be executed with an improper form, provided that you give it all you've got. (fitnessandpower.com)
This is very common during max attempts, or when someone is trying to lift a weight that's too heavy for them. (bodybuilding.com)
Visualize what you want to do in the next set, focus on your goal, this can include technical aspects, lifting as fast as possible or simply «surviving under the bar» if you are doing max attempts or multiple repetitions working with RM loads (christianbosse.com)