Danai places 12 skulls + 4 broomsticks + 12 spiderwebs + 1 cauldron = <<12+4+12+1=29>>29 decorations.
She also puts up twice as many pumpkins around the house as she put spiderwebs, 12 x 2 = <<12*2=24>>24 pumpkins.
Danai will also add 20 + 10 decorations to the 29 + 24 decorations already up = 83 total decorations Danai will put up.
#### 83