First (at home) retreat. My plan any good?

[Waken]

Hi guys, as I have - starting tomorrow - 8 days of holiday I wanted to turn it into a retreat at home. My plan is to do mostly strong determination sits with the do nothing technique of around 3 hours, and maybe I'll do some attempts to do some longer sits as well, as well as shorter sits for when it gets too gruesome :-)
In addition to it, I was thinking about doing shamanic breathing every day in the morning, starting with an hour and building it up by 5 minutes or so. The idea of doing it in the morning is that is gives a altered state of consciousness, which might make it beneficial to have the meditations after it.
In the 6th day or something, I'll use some shroomies in addition to the meditations, I'll probably leave the shamanic breathing out that day.

Some things I'm not sure about. Are strong determination sits the way to go when doing a retreat, or best to do shorter sits like 1 hour?
I think doing shamanic breathing (and shrooms) in addition to the meditations is fine or good, but if for some reason not beneficial, I'd like to hear it.

It's my first retreat, so don't know well what will happen, but I guess it will give some good yield..
Thank you