Everyone knows that wearing a condom is one of the most effective ways to prevent unwanted pregnancies and sexually transmitted infections. However, it's what you don't know about putting on a condom that can change your life.

When used properly, condoms have a very low failure rate. Unfortunately, most of these best-case scenarios were achieved in lab settings. In the real world, people make all kinds of mistakes that can lead to condom failure. When comes to wearing a rubber the right way, it's what you don't know that can really hurt you. (For some background reading, check out The Ultimate Guide to Safer Sex.)

What You Don't Know

First, let's address the misconceptions about condoms - and there are many - that can get in the way of using them consistently. After all, the first step to using a condom properly is to actually put it on before having sex.

Misconception: A man loses all sensation when he puts on a condom.

This is one of the most common excuses that men use when they don't want to wear a condom. Many women believe this line - and end up regretting it later. A study released in January of 2013 finally put this common myth to rest: condoms do not decrease sexual satisfaction for men or their female partners. So there, it's official. Some condoms even have pleasure enhancers. So, rubber up already!

Misconception: Putting on a condom kills "the mood".

If you're in a desperate hurry to get down and dirty, a condom can feel like a burden, and fiddling with a plastic package can feel less than romantic. But you know what's a real libido-buster? Try an STD. Or an unwanted pregnancy. Plus, whether a condom kills the mood is really up to you. Make a condom part of foreplay by sensually rolling it on. (Use your imagination here, ladies!)

Misconception: A latex allergy puts the kibosh on condom use.

First, latex allergies are extremely rare. What's more common is a sensitivity to the spermicide that's often added to lubricated condoms. If you or your partner gets a reaction from a rubber, try a few different non-spermicidal condoms and add your own water-based lube. If a true latex allergy is really the case, there are also condoms made from non-latex materials, like polyurethane and lambskin. (Lifestyles also makes a new polyisoprene condom that's getting rave reviews.)

Misconception: You can't put on a condom if you don't have one.

OK, this is technically true, but we're putting it in the misconception category unless you live in, say, a remote village in Yemen. If not, this excuse is just doesn't hold water. Condoms are easy to find. You can buy them in a supermarket, convenience store, pharmacy, clinic and even from the vending machines you'll find in many public restrooms. If you think you'll be getting lucky, keep a couple on hand.

Misconception: It's a good idea to carry a condom at all times.

This is somewhat true, but it depends on how you're carrying it. Although any condom is better than no condom, these love gloves should be stored properly for the best results. Condoms stored in areas that are warm or damp, for instance, can begin to weaken and become brittle with time. This can lead to holes or tears. If possible, condoms should always be stored in a cool, dry safe place.

Misconception: A man doesn't have to put on a condom until he's ready to climax.

Um no. A man should put on a condom before any sexual activity takes place, not just before be ejaculates. That's because pre-ejaculate, the clear fluid that can seep out of the penis prior to ejaculation, carries a small amount of viable sperm. Although the chances are small that this amount of sperm can get a woman pregnant, it is still possible, as is the risk of transmitting a sexually transmitted infection. (Learn more amazing facts about the males species in 10 Things You Don't Know About Penises.)

Misconception: Two condoms are better than one.

While wearing two condoms may seem like the logical way to add an extra layer of protection, this couldn't be further from the truth. Some people also think that this tactic will reduce a man's sensitivity, helping him to last longer. The fact is, wearing two condoms is actually worse than wearing just one. That's because the friction of latex against latex can weaken both condoms, making them more prone to breaking. One condom will do the trick. And if a man's concerned about too much sensitivity, there are products to help with that problem as well.

Misconception: You can take a second round with the same condom.

Reusing a condom is, well, kinda gross, whether the man's ejaculated or not. It's also kinda risky. The condom may be weaker the second time around, making it more prone to breaking.

How to Put on a Condom...Properly

Now that we've quashed some of the most common excuses for not wearing a condom, it's important that when you do use a condom you use it properly - perfectly - each and every time. Before going for the real thing, feel free to practice on yourself, your partner, a dildo, or a choice piece of produce from the nearest supermarket.

Step 1: Visually inspect the condom package. If it's ripped, damaged or the expiration date printed on it has passed, toss it.

Step 2: Open the package. Tear it open with your fingers along the dotted line at the top. Never use anything sharp to open a condom package - that includes your teeth.

Step 3: Place the condom over the tip of an erect penis, with the rolled rim on the outside. It should look like a little hat on Admiral Winkie.

Step 4: Remove the air from the tip of the condom.This can be done by pinching the tip gently with your fingers. This provides some room for semen, making the condom less likely to break.

Step 5: Roll the condom carefully down the shaft of the penis. If you use your mouth, just keep your teeth clear. If a condom gets damaged while you're putting it on, don't take any chances - remove it and start over with a fresh one.

Step 6: OK, so we added a bonus step, but removing a condom properly after use is just as important as putting a condom on properly. It should be removed immediately after intercourse. To ensure that the condom does not leak or come off during removal, grasp it at the base of the penis as it is withdrawn. It should then be removed, tied shut and thrown away.

Got it? Repeat as needed. Just make sure you do it right.