A: This is a common problem for solo acoustic guitarists who use alternate tunings, particularly live on stage, where you have to retune quickly between songs.
Our best advice consists of three suggestions:
1. Always tune up to pitch. So if you are tuning to a lower note, drop the string down past the desired pitch and bring it back up to where you want it. This will likely solve most of your problems, especially with the wound strings.
2. Practice! Believe it or not, re-tuning to an alternate tuning is a skill that can be learned and improved. With practice you’ll get faster, you’ll learn to count the turns it takes on the tuner to get the pitch close to where you want it for each tuning, and your ear for tuning will improve. It’s especially valuable to practice going from tuning to tuning in the same order as you would in your set onstage.
3. It helps if you can arrange your set so that songs with similar tunings or the same tuning are together.