Make your stranded end nice and long and easy to “comb” and flatten out. Get all your pairs lined up and in order and flatten the wires together on a table or other work surface.

I usually cut about 3 or so inches of sleeve off the cable to expose the strands. But same thing applies if you can only cut an inch off, just a little more difficult.

Assuming you have passthrough rj45 ends or whatever they’re called, you can just slip on your end and crimp and let the tool trim the excess wire.

If you don’t you get to go through the process of trimming down and getting the tiny stubs to stay together enough to slide into the connector.

Example from eBay listing