That's funny. I've had this conversation with a guitar buddy of mine. He loved to use alternate tunings. I can't stand it. But I'm more of a lead player. I need to count on my scale shapes in a hurry. If I adjust the tuning, then I'm scrambling during the solos.
I like 75754. It's the tuning Bruce Cockburn used to play "Foxglove".
You have to step down the Bass E 2 steps to keep from tuning the D and G strings higher than their designed open pitch. Use your pitch pipe to guide you in observing that limit.
If you have a circular chromatic pitch pipe, you can determine the notes in your open tuning by matching the pitch. From there you can find what notes are being made further on the fret board with melody or chords.
Alternate tunings have to be tuned from the standard pitch of each string or a lower pitch than the standard pitch for each string. This is the main rule to protect the bridge from excessive string tension. Some guitars are best left in the standard tuning simply because the action is optimized for that amount of torque on the neck. In slack key the strings buzz on the frets. My Ovation Adamas has this characteristic, but not the Martin D35.