How to make crossover cable  ?
                 An Ethernet crossover cable is a type of Ethernet cable used to connect computing devices together directly. Normal straight throughor patch cables were used to connect from a host network interface controller to a network switch, hub or router. 

                  To make a "Crossover" cable you change the pinout connections on one end of the cable. If you do it on both ends of the cable you have crossed-over the crossover and now have a straight-through cable.Pins 1 & 2 from one end are connected to pins 3 & 6 on the other end, and pins 3 & 6 from the first end are connected to pins 1 & 2 on the other end. Pins 4 & 5 and 7 & 8 don't change.

The pin outs looking from the bottom of the cat 5 ends (White/Orange starts on the left) are as follows:

       Standard End                          Crossover End

       Pin 1 White/Orange                   Pin 1 White/Green

       Pin 2 Orange                            Pin 2 Green

       Pin 3 White/Green                    Pin 3 White/Orange

       Pin 4 Blue                                Pin 4 Blue

       Pin 5 White/Blue                      Pin 5 White/Blue

       Pin 6 Green                             Pin 6 Orange

       Pin 7 White/Brown                   Pin 7 White/Brown

       Pin 8 Brown                             Pin 8 Brown

difference between cross over cable and straight cable?

crossover cables must be used between 2 devices from the same level like (pc & pc - Pc & router - router & router) 
but strait through cable used between 2 different levels like (pc & switch - router & switch ) ,like a router to a computer.