Basically this is how I do it at work.
I do the following after every shave and tend to find if the client has any "blood spots" it stops them straight away.
2 cold towels and the whole face rub of alum. At this point there should be no more blood. Really cold air from the hairdryer to dry and cool the face and then once its dry a generous splash of witch hazel.
This is then followed by more cold air till mostly dry.
I sometimes then use some talc on the clients face, this is mostly to make sure the face is clean as it will remove any loose hairs which may be on the face (you tend to find hair appears out the blue in a barbers) but it also helps in cooling the face.
Then some aftershave balm. Another quick blast of cold air to dry up and cool down further.
If there are some proper "cuts" (normally minor, I wouldn't say I have ever gashed anyone, lol) I use a styptic match after the witch hazel part as if you havent stopped the blleeding by that bit the match will definitly.
I do find though that if I think a cut is gonna cause me problems I tend to put a tiny bit of tissue on it while I get on and finish the shave. The tissue on the face even for those few minutes does work wonders and also makes things look neater as you work.
Anyway to this day (touch wood) using the above none of my clients have ever left the shop with any eveidence of any blood.