I know this has been discussed in this forum, but I will sum this up as I understood it, so maybe it can save someone the time reading through all the posts.
So, if I am after simple and efficient extraction, what about this one?

1. Drying mushrooms on the air, as much as possible
2. Drying them again, with anhydrous MgSO4
3. Grinding them to the dust
4. Doing 3x24h soaks in pure methanol, with a bit of ascorbic acid, with occasional shaking
5. Decanting/filtering methanol and discarding the rest
6. Full evaporation of methanol in vacuum
7. Redisolving the residue in 40% ethanol to make solution - 1ml/1g of original material

So possible questions ...
1. Any tweaks to this simple procedure?
2. Is heating preferable for ethanol soaks, possibly for last pull?
3. Is ascorbic acid necessary, if there are almost no water and enzymes in the result, so oxidation is going to be minimal?
4. What about possible washes before methanol soaks (acetone, chloroform). Is it worth it?
5. What might be the estimate of difference in effectiveness of simply grinding the shrooms properly and using ultrasonic lysing?

Cheers for any inputs...

Psilocybin extraction and purification is not as straightforward as it seems. Look into purifying zwitterionic compounds and you will see why.

Thank you concombres for your answer.
I am not sure I get what you meant. I am not willing to get crystals as in case of dmt or mescaline. I only want to reduce the amount necessary for ingestion, so not a problem for me to end up with some active tar, even when it contains just 10% of active compound.
Is anything bad on beforestated method? There seems to be quite consensus (not only) in the forum, that simple methanol extraction is effective for psilocybin. Though does not provide pure result, it still offers quite strong extract.

Well, finally tested.
I had problem with vacuum evaporation, so evaporated it just in the water bath.
After full evaporation of methanol, vodka was used as solvent to make 1ml/1g of original material. In my case estimated 10mg of psilocybin in 1ml.
Stored in small 3-5ml bottles with minimum air in the freezer for 4 months.
Tested 3ml of final solution yesterday and I can confirm it seems to be in par with experience on 3g of raw shrooms.
Final product tasted lovely, no nausea that is always there with raw shrooms.

***Just in case anyone would like to do this, please be aware of the toxicity of methanol. It is absorbed throug skin and lungs too.

Just regarding the drying process MgSO4 is indeed a potent drying agent but for liquids - that means you would stirr it strongly with some MgSO4 added. But if you put your mushrooms in a drying chamber then drying efficiency is low. Because of that for these purposes CaCl2 is the way to go - it comes with a high porisity and therefore increased surface for water uptake when not immersed in liquid stuff.

But even if that drying process would have been not 100 % then methanol should denature everything that could react enzymatically afterwards I guess

how much methanol to use for each soak? how much is a bit of ascorbic acid?