Must the chalice be filled with real blood or can it be any other liquid?
I’m sure this is a matter of personal preference.
One practitioner on this site that I’ve read will give a drop of her own blood into a chalice full of cranberry juice mixed with water and by her intention transubstantiate it to blood.
Similarly, Catholic priests (who do have real spiritual power) will use wine and using magic with transubstantiate it into blood for their communions.
Think about how much blood it would take, dripping out slowly, drop by drop, to fill an entire chalice even if just a small one? That’s a lot more blood than you may realize. Most chalices have a 3 inch cup or bigger. You’d have to bleed an awful lot to fill one up and that much blood loss would not kill you, but for some, would definitely be enough to make them weak or faint.
Unless you are just unusually masochistic and love cutting the fuck out of yourself, most people would opt for a few drops of blood mixed in with wine, grape juice, or cranberry juice.
For future reference though, if ever making an offering and you really want to make the spirits feel drunk-in-love (not to be confused with Beyonce’s version of drunk in love LOL) try mixing some of your blood with brown liquor.