I usually use my standard dose amount for everything I make - makes things easy to remember for me. I use 150 grams popcorn trim (usually dry ice hashed first) to 64 oz butter (coconut oil, grapeseed oil, milk, cream, etc) If you are making ice cream, I would do either whole milk or heavy cream, or even both.
very simple...grind and decarb material to be used. Place in container with milk, cream, etc. Simmer over low heat for an hour then shut off. You will want to watch close to make sure it does not boil, as it will happen very fast and go all over your stove. You will want to strain it while it is still hot or at least warm for best return. You can use a few layers of cheesecloth in a mesh strainer set over a big bowl to pour most of it through. When you get down to where the material is, if you don't have some sort of press, you will want to squeeze it out through the cheesecloth in small batches - if you try to do it all in one squeeze, you wont get all your milk back out of the material.
If not going to use immediately, cool by placing bowl in an ice water bath and stirring often until cool enough to put in fridge. There are many things you can make now besides ice cream