My first attempt!
Macrame Heart Coaster

Only takes at most a couple of hours.
Cord width: 3mm
Number of cords: 12
Length of cords (estimated): 150cm.

After finishing, I reckon 130cm is enough.
Frills at side - cut 8 x 20cm lengths.

So, did some measurements, here is what I came out with to economise cord lengths.
Cord 1, 2, 3, 10, 11, 12 : 80 cm
Cord 4, 9 : 100 cm
Cord 5, 8 : 90 cm
Cord 6, 7 : 110 cm

19.02.20 - Made another using these measurements, worked well!