Have a sitter - someone you deeply trust and preferably one that understands the level of commitment. It sounds like you're not but don't be in any rush and maybe even pick a date so that you can emotionally prepare.
As famine suggested, start very small. Depending on the efficiency of your administration method, this can absolutely be as small as the low end of what famine suggested here. If you're acquainted with N,N, 10% of your high end dose of that is probably a safe starting amount to build from. Hoping others will chime in here to comment on that figure.
In addition to the 4hr fast, I would suggest vegetarian diet for a couple days before. Maybe extreme but I like the idea of having no meat anywhere in the digestive system for the experience.. ymmv ofc.
And this is probably very 'duh' but I'm gonna say it anyway just in case bc I'm new here and all: NO MAOIs!!. <shakes finger like worried parent>
Oh and TRIP REPORT or it didn't happen
