I do have a lot of tips for self guided experiences, just not for guided ones.

For instance:

- Do not ever do a lot at once. Start with a little and feed up to the required effect step by step.

- Have someone reliable to watch over you during the entire experience

- Choose the environment appropriately to your substance of choice and the purpose of your experience

- Plan your experience to work regardless of whether you ingest any psychoactive substance or not.

- Stay properly hydrated

- Learn what you can about the substance and it's positive and negative effects, contraindications and adversarial substances beforehand.

- Have a contingency plan for a possible unpleasant experience

- Do not stress about the experience or the substance. Go into it with a light mind. Be prepared, not stressed.

- Don't use any psychoactive substance if anything feels wrong. Don't start or continue unless it feels right. It is better to miss out or let a bit of it go to waste than to have a bad experience.

- Don't repeat use frequently. I'd go for at least two months between sessions. Less is better.

All of the tips should apply regardless of substance and your reason to use.