Summarize:

It is important to wait so that the debris in your inner ear can settle before you inadvertently shake it up again. This helps to avoid any rebound symptoms of vertigo right after leaving the doctor's office (or right after performing the maneuver on yourself). After about 10 minutes, the debris should be settled and you are safe to proceed with your day as normal. After you get the maneuver performed on you by a doctor, you will be given a soft collar (also known as a soft neck brace) that you will be asked to wear for the rest of the day. The collar will help to control your head movements so that you don’t accidentally move your head in a way that makes your inner ear crystals get out of place again. The night after you have the maneuver done, you should plan on sleeping with your head kept up at a 45 degree angle. You can do this by propping yourself up with pillows or by sleeping in a reclining chair. This means keeping your neck as straight as possible, with your head facing forward. Avoid doing things like going to the dentist or hairdresser, where they tilt your head backwards. You should also avoid exercises where your head moves around a lot. You should not tilt your head back more than 30 degrees.  When you shower, position yourself so that you are directly under the shower head so that you don’t have to tilt your head back. If you are a man who needs to shave, bend your body forward rather than tilting your head to shave. Avoid any other positions that are known to trigger your BPPV for at least one week after the Epley maneuver has been performed. After you have waited for a full week avoiding symptoms that are known to provoke your BPPV, try an experiment and see if you can cause yourself to experience vertigo again (by assuming one of the positions that may previously have triggered it). If the maneuver was successful, you should not be able to trigger the vertigo in yourself at this time. It may return again down the road, but the Epley maneuver is highly successful and serves as a temporary cure for BPPV in about 90% of people.
Wait for 10 minutes before leaving the doctor's office. Wear a soft collar for the rest of the day. Sleep with your head and shoulders in a mostly upright position. Keep your head as vertical as possible during the day. Test the results.