Gather Ethernet cable, RJ45 connectors, crimping tool, cable stripper, and cable tester

Choose the wiring standard: T568A or T568B

Strip about 1 inch of the outer jacket from both ends of the cable

Untwist and straighten the eight inner wires

Arrange the wires in the correct color order for the chosen standard

Trim the wires evenly to the same length

Insert the wires fully into the RJ45 connector

Verify each wire reaches the front of the connector and stays in order

Crimp the connector with the crimping tool

Repeat the same steps on the other end

Test the finished cable with a cable tester

Recrimp or remake any end that fails the test