It depends on what compound your mixing, and how concentrated your finished product will be...
For an example ill make up testosterone Enanthate 250mg/ml...
Things you will need......
-testosterone Enanthate powder
-carrier oil (I use mct oil) lots of people use grapeseed oil. I like mct because it's thinner.
-benzyl alcohol(to keep solution somewhat sterile)
-benzyl Benzoate(solvent to break down powder)
-hotplate with magnetic stirrer
-autoclave(I use a steroclave)
-bottletop filter with 22 micron PVDf filter
-vaccum pump to run your bottletop filter.
-beaker to mix your product on your hotplate.(I use 500ml)
-10ml bottles with caps stoppers and a cap crimper..
-scale to weigh everything out.
Okay so if I'm making 100 ml of testosterone Enanthate at 250mg/ml I would mix my ingredients like this..
* first I would put 61.25ml of mct oil in my beaker on my hotplate, with magnetic stirrer running... I have the hotplate on but very low I gradually turn it up, the goal is to get it mixed with the least amount of heat as possible, as too much heat can break down your gear..
*then add 18ml benzyl Benzoate(18%) to your beaker into the mct oil that's already mixing.
*then add 2ml benzyl alcohol(2%)
* once allowed to mix up for a minute add 25 grams testosterone enanthate powder and let mix in and very gradually bring the heat up try to stay under 130°F if possible... I just slowly bring it up until product is dissolved...(you can use solvents like ethyl oelate)
* once your finished product is mixed thoroughly you can let it cool down a bit then run it through your bottletop filter.. the product that runs through the filter is good to be bottled... I use a pipette set at 10ml and put the finished product into the bottles I pulled out of the steroclave and put the stoppers that have been soaking in benzyl alcohol in the bottles after they dried... if you want to be super sterile you can use a laminar flow box to work in front of to keep things extra clean.(will never be fully sterile). Anyway put stopper on 10ml bottles with finished product and put caps on and crimp them... Wallah
So reading this I'm sure you can see I'm far from being a professional, I don't know chemistry, and there are lots of different ways and ratios and different stuff you can use.. but this is how I do it
To add up formulas you can use a simple aas calculator like this...
steroidhomebrew.com
I also look up different formulas on different clearnet forums.. lots of info out there on mixing different compounds at different concentrations... just gotta do some searching and reading...