A very easy method for blood drops. I'm sure you could replace this with Nurgle's Rot, or perhaps gloss and then paint with Contrast for all sorts of effects.

1. Cut or pull a hair out of your head! If you prefer, fishing line would likely work. It just needs to have a bit of it's own spring to it.
2. Superglue it to the place you'd like it to go. Tweezers help a lot here.
3. Once the glue is dry, cut the hair to the desired length. Scale is really important I've found. It's not going to drip forever!
4. Optional step: I find that using Flesh Tearers Red to flick and draw quick swipes of blood up the weapon before the Blood For The Blood God stage adds depth.
5. Coat the hair and surrounding areas with Blood For The Blood God (or Nurgles Rot or even Ardcoat if you want clear then paint later). Draw the blood towards the bottom.
6. Repeat the process, allowing it to dry and then topping up until you're happy. Again, scale is important. If you want it particularly gory, dabbing on the Blood For The Blood God in different areas builds it up.