The right way:
1. Checking the expiration date on the condom packet. Looking to make sure it has a little symbol on it saying it meets standards.
2. Pressing on a corner of the individual condom packet - if the air fills up the other corner, you know there is no puncture in the packet.
3. Making sure when tearing open the packet not to rip the condom.
4. Carefully looking at the condom to make sure you're putting it on the right way. It should be able to unroll smoothly over the penis. If the guy has accidentally put it the wrong way round, he needs to throw the condom away and use a fresh condom - semen may have gotten onto the inside of the condom if he tried to unroll it the wrong way.
5. The tip of the condom needs to be squeezed when it is unrolled. This leaves a gap for the semen to enter. Semen ejects from the penis at an unbelieveable fast rate, and this force will just pop the condom if there is air in the tip.
6. When the male withdraws, he needs to make sure to hold the condom onto the base of his penis so there's no chance of leaving it in the female or spilling.
Also - never, ever use two condoms. The friction between them hugely increases the chance of the condoms tearing. Male condoms are 98% effective when used correctly, and help prevent both pregnancy and STDs.