How to stock faster?

Hello just completed my 2nd ON stocking shift was able to do 2 pallots by myself and a 3rd with 2 other people how do I get faster at this I was before hand just scanning one box and putting it up but after my lunch break at 3 I decided to go get another buggy (at my location I was told to grab a buggy to put cardboard and plastic in but I saw my trainer grab 2 for herself didn’t know why till later on my 2nd shift) and now I just try and find a couple box’s that go in the same aisle I see my trainer is able to just grab a couple of box and go how do I know which box’s would be in the same aisle cause I could scan one box see where it goes then grab a couple box’s to bring with me but I can’t tell what box’s would have the same stuff to go into the same aisle