Fuck it... I'll spoon-feed out of boredom.
A basic AAS "brew" consists of 4 ingredients: carrier oil, benzyl benzoate, benzyl alcohol and a raw hormone.
The carrier oil is just that, it carries the solution you'll make with the BB and the hormone. It can also assist with bringing the mixture into a solution, depending on the compound being made.
The BA is meant to create a sterile solution. 1-2% of volume is typical.
How do you bring the hormone and the BB into a solution? Depends on the hormone and/or ester. Some hormones don't actually need any BB at all to come into solution. Others need quite a bit, they may even need a stronger solvent to bring the hormone into solution.
A basic compound like Test Cyp needs an "average" amount, it can be done with as much as 15% BB. However, if your house gets cold it can fall out of solution aka crash.
An exotic compound like test base needs a lot of BB, some brewers use 40% in addition to other solvents like guaiacol and ethyl oleate. Even with all of that, some will still have trouble getting it into solution.
Of course, I'm leaving out a bunch of information like heat, filtering, etc... I'm not that bored.