If you cannibalize old devices for example you will sometimes cut yourself. Of course you don’t want to have a longer break so here is a guide how to close a small wound quickly.
If it’s just a little wound (at best a cut) you can wash the wound (nothing should be in the wound) and your other hand and then press your finger on the wound so the edges of the wound are pressed together. You mustn’t press softly but also you needn’t press ultra-hard.
After some minutes (1-3) you will feel the hurt ceasing but press a bit longer.
Afterwards remove your finger and voila, it doesn’t bleed anymore (but don’t strain it).
This technique is also useful for stopping the bleeding after removing cannulas (with injections I’m not sure if there are sideeffects).
Disclaimer: I’m not a physician. I’m just a tinkerer who learned it from one.