Well, ideally, you want to avoid the misloads completely. But, we are only human.
If you get help, make sure management is aware of that because you can not be blamed for others mistakes.
So, until you make seniority, slow down a bit and pay closer attention to the labels.
What has worked for me is writing both the car number and pal number on the box - just before placing it on the shelf.
Also, management encourages carrying more than one package at a time. So, if you do, make sure they're for the same car. Don't grab packages for car 8 and 9 and bring them both into 8. Instead, leave the package for 9 and make a second trip.
Another "solution" management has encouraged in the past is reading the label out-loud as you enter into the car.
These tips work even better if the car number is posted somewhere obvious inside the car.
Finally, if management is distracting ...err... talking to you, stop what you're doing until the conversation is finished.