(note - 1st draft)
After hundreds of brews, I figured I'd finally write an outline for how I have learned to brew.
I will be writing this from perspective of my personal typically brewed sacrament, which is Acacia Confusa + Syrian Rue, in 'Haoma'; 'formosahuasca' among other various other names may also be used to refer to this brew.
This guide will also work with Rue or Acacia alone, or with other, similar entheogens, such as rue and mimosa.
'Ayahuasca' is an inaccurate name for any brew not containing B. Caapi vine, but is still used somewhat often to refer to other DMT/harmala brews.
Overall the main goal is psychoactivity with limited nausea.
I have worked with whole bark strips, shredded bark, and powdered, and find any to be effectively usable for brewing. As long as it fits in the pot, basically. This is up to your sensibility and/or available mat'l to determine.
I prefer to use whole syrian rue seeds instead of crushed or powdered, out of personal preference.
Dosage is also variable but the same process works for any amount of material.
Time is a variable that is very circumstantial and personal choice; Brewing for 1hr may be as effective as brewing for 6hrs, depending.
No one guide will be able to get to all factors you may face while brewing, but I will try; nonetheless, this is a very spiritual process, and you will have to do it yourself to learn the finer points of the process... However, overall it is quite instinctive, and very easy to do, as the simplest method of extraction.
With all of that taken into consideration, I will outline my process.
Doses must be weighed and added to the pot. This is, of course, yours for the choosing.
To recommend a starting dose, I would choose to brew 5g of rue seed, to 15g acacia. This may or may not be all drank, however small sips should be used first, and then more worked up to.

I brew the Acacia first, as the rue tea may be brewed fairly quickly. Acacia/Mimosa may be brewed however long as you see fit; personally, I let the pot boil for a solid 2-4hrs, and I do not use an acid such as vinegar, finding the taste and astringency to be too unpleasant, and adding to nausea. I believe saving the material after the brew is done is for the best, so the next time you put a brew on, there's already material in the pot to work with. However if you choose to discard, this is understandable as well.

Maintaining the water level is a trick that will have to be learned by instinct; there is no true set formula for this, but the goals will be to not allow the pot to boil over, or go too low so as to burn the material.
Start with a large amount of water and allow it to work its way down. After additional water is added to the reduced liquid, gradually use less than you started with.

For a general rule of thumb, 1 cup of water to every 5g Acacia used should be effective to begin with, with water added thru-out.
After the Acacia tea has started to take shape, around an hour of boiling or so, color change will be notable as the bark will start to extract, and now the rue tea may be started.
I like to brew them separate so I am writing with this method in mind, however, simply throwing both into the same pot may be done to good effect as well.

Rue does not need be boiled for more than an hour unless a large batch is being made. Use perhaps 1 cup for each 3g rue to start.
After it has boiled down to a low level of water, with at least one addition of water being added then reduced again, this liquid is ready to be added to the boiling acacia pot. I like to give the seeds a stir and pour them along with the liquid in, allowing them to brew in the Acacia further.
You may also keep the rue separate and filter then drink it first.

At this point several cups of liquid, containing brewing rue+acacia, are in one pot. This will be your drink.
I like to season the liquid with spices such as cocoa powder, nutmeg, allspice, cinnamon, and honey. Consideration for harmala interactions should be given to substances such as vanilla and cacao. The honey will also make the liquid sugary, which should be considered for storage purposes, and also comes into play later when reducing to final volume.

Once the boiling liquid has finally reached an amount of water approx ~ >1 cup in volume, take the pot off the heat, and allow to cool until near room temperature.
Allowing the brew to sit and extract at this point is optional and ideal. Adding water and allowing to sit overnight is best.
Filtering is the next step. I have found, after using many materials, cotton cloth is the best to use, with a thin white shirt dedicated and stained for the purpose being my usual filtering cloth.

After carefully filtering into a selected container, I find a spouted measuring cup best, the liquid is ready to reduce for a final time, or be drank as is, or both.

If reducing a final time, allow the liquid to boil but be very careful not to reduce to the point that it becomes a 'goo', and starts to burn, as the DMT will be very easily destroyed by the heat it contacts at that point.
Also noteworthy is if honey is added to the brew (strongly recommended) and the final liquid is reduced too far, it will become thick and syrupy, which is not pleasant to drink.

Once you've got your final drink ready, I recommend allowing it to sit, as sediment will settle out of it, unless filtration was very thorough. Now, when ready to drink, fasting beforehand is always important, along with harmala interactions being respected of course.
When it actually comes to the 'moment of liquid truth', I do as much possible to not taste the liquid.

I will take a spoonful of honey, and swish it around my mouth a bit with water or saliva, and this will coat the tongue and throat so as to 'turn off' those bitter detecting tastebuds. Then, have a swig of the tea. Start with small amounts first, as each drink will always be something different of a dose. Immediately after this I will drink a strongly flavored juice, and smoke cannabis, with cannabis always being a crucial part of any day/ceremony/sacrament.

Enjoy, and be safe ...

Awesome. A very simple to follow recipe, thank you.

What is an average time line like from first sip to baseline?

Depends on dose, I find higher rue doses are more effective than higher acacia doses often times.
I've had 2 day experiences, or an hour long glow, after drinking. Very circumstantial and seems almost arbitrary, after hundreds of drinks....
There's no escaping a high dose though lol, have to know what amounts you used, especially with minimal liquid shots after effective volume reductions.

Thank you for your detailed brewing instructions. I have read quite a bit over the last few months, but one questions comes to my mind that I have not found an answer to yet. Since caapi vine seems to be readily available for order, at least where I am, is there any reason why mainly Syrian rue is used in combination with ACRB ? Is it just personal preference or are there any other reason why not to combine it with caapi but rather uses rue? Thanks you in advance if any one could comment on this.

I use rue because its cheaper, simply, as well as much more potent by weight, this helps make it faster to brew ime as well.
I have used ayahuasca and Acacia, as well as acacia-rue + ayahuasca-chacruna, brewed seperate, then added together and reduced on a final boil.
All in all, means to an end. Different keys, different doors ,...