There are many reasons you can fail at a deadlift. One reason might be your setup and technique needs work. That’s just one reason why it’s really important to practice actual deadlift. On my deadlift day I start with the conventional deadlift and then pick a movement to focus an area of the lift that is weak. Here are some exercises that will help you fix those weak points off the floor and increase your deadlift.
I love deficit deads for building strength off the floor. Stand on a 100 lb plate, or something lower, as low as an inch and pull. If what you’re standing on is too high, it can cause you to round your lower back, causing low back pain. I recommend something about 3” or less. When you do these, make sure you are stopping at the bottom, and letting the weight rest, if you let the weight rebound off the floor, you are defeating the purpose of the movement. Deficit deads will help you build strength through a lower starting point.