What are negatives?
With this strategy you will train with a weight greater than what you can lift.
You will need a training partner.
Put on between 10 and 30% more weight than you do for a given exercise and ask your training partner for help to provide obvious help in the eccentric phase of the exercise but minimal help (or none) in the negative phase, or, concentric.
Example
Negatives
You put 140kg on the flat bench press.
Your training partner helps you bring the bar up, but you hold the bar down with little or no help.