The American Security Institute recommends carrying the largest size pepper spray that is practical and legal for you. Most 2 ounce sprays are about 4" long and 1" in diameter- small enough to clip onto a purse or a belt. If you find this size inconvenient or impractical, carry a keychain spray. The biggest advantage of the keychain spray is that you're not likely to forget it.
Unless you have no other choice, do not carry a pepper spray in your pocket! Too often the spray cannot be retrieved quickly enough to do any good. Remember, most physical assaults occur very quickly, often giving the victim a second or two, at most, to react. As you'll read later, there's a way to handle this, but only if your defense spray is readily available. The other reason you shouldn't carry the spray in your pocket is the possibility of forgetting it the next time you go out.
For women, the obvious place to carry pepper spray is a purse. What is not so obvious, is HOW to carry it in the purse. Don't let the spray sit at the bottom of your purse. The time it takes to find and retrieve it can be all the time an assailant needs to overpower you or even steal your purse!
Pepper spray carried in a purse should be clipped to the front end of an inside pocket, flap, or divider. Clip it so that the unit itself is inside the purse, easy to access, pull out, and use in a few seconds. You may consider holding it in your purse as you're walking. A purse with a long strap slung over the shoulder is ideal for this purpose. An assailant just might hesitate if he sees you're prepared to deal with someone just like him.
A recommended alternative to carrying a purse is a small waist or "fanny" pack. The belt of the pack is ideal for carrying a pepper spray and there's little danger of a "purse snatch" attempt on the pack. A note of caution: If you do use a waist or "fanny" pack, don't carry any defense spray in the open where it can be seen. You will lose the important element of surprise, (covered later), and it might even be stolen! Cover it up with a coat, jacket, sweatshirt, etc.
If you're going to carry the pepper spray on a belt beneath a jacket or coat, attach the spray upside down. If you experiment with this, you'll probably find it much easier to "draw" the spray downward off the belt, rather than upward. Also, if possible, position the spray in its holster so that when it's grabbed and drawn, it's already in position to use without having to turn it or rearrange it in your hand. Experiment until you can quickly draw the spray, raise it up, and shoot it in one fluid motion.
Practice the same drill noted above, if you carry the spray in your purse. Keep in mind that you want to retain possession of the spray even if your purse is grabbed and yanked away. The spray should be positioned and clipped onto the purse in such a way that, when you have hold of it, any downward yank of the purse will allow the spray to come off in your hand.
Anytime you're on foot, such as walking to your car, leaving a restaurant, shopping, jogging, etc., alone or isolated; you should have the spray ready to use in an instant. Whether it's attached to your purse or belt, or on a key chain makes no difference; have it ready! The time you may need to react to an assault may be less than a few seconds.
It's also very important to mentally rehearse exactly what to do in case you need to use the spray. Practice against an imaginary assailant until you're comfortable with your ability to use the spray fast and effectively. This practice could make the difference between becoming a victim and surviving a hostile confrontation.