Order a 3-month supply rather than 1-month supply of each medication you take. Most doctors will ask if you want a prescription written for 1 or 3 months -- and most insurance companies cover either. As a bonus, you may get a price break by ordering the higher quantity.
Have your doctor write prescriptions for the largest, reasonable quantity. For example, if you take one of your medications 2 or 3 times a day depending on your pain level, have the doctor write it for the maximum dose. You can still take just two but you will be able to save extra pills for your stockpile.
Refill prescriptions as soon as they are due. Don't wait. Most prescriptions allow you to refill a bit early. Check your insurance for specifics but always take advantage of refilling as soon as possible.
Never let a prescription expire. You are wasting precious time if you let prescriptions expire. You or your pharmacist will have to contact your doctor for permission to refill if it expires. This can take a couple of days.
Consider filling your prescriptions at a local pharmacy. Mail order pharmacies are convenient and sometimes a little cheaper but they take extra time. You can't get drugs immediately without extra cost to expedite shipment. You're stuck waiting for the mail to come. Not good if you're in a rush. Even if you choose to use mail order on a regular basis, try to have a prescription on hold at a local pharmacy in case you needed a refill quickly.
Always ask your doctor for samples of the drugs you take. Doctors often have samples available which they get from pharmaceutical salesmen, especially for brand name drugs. If you can get free samples, that adds to your emergency stockpile.
The Bottom Line
Essentially, you want to have enough pills in reserve -- especially the ones you couldn't do without. How do you know you have enough in reserve? Ask yourself if you would have enough medications to last one week. That's the least amount that you need on hand. More is better.