http://blog.organized-living-solutions.com/2012/02/chaos-and-crochet.html I used a 3.5 hook, but you can use whatever works with your preferred wool.
Start off by making 5 chains and closing them into a circle with a slip stich
Then crochet 5 single crochets into the centre, then 2 chains, then again 5 single crochets into the center. Close the round with another slip stich, followed by a chain, into the first single crochet.
Then make 1 half double crochet, 1 double crochet and 2 treble crochets into the next crochet.
Then put 3 treble crochets into the next crochet
Then 2 double crochets into the next
Then a half double crochet into the next
Then into the two chains you made earlier crochet 1 double crochet, 1 chain, 1 treble crochet, 1 chain, 1 double crochet
Into the next crochet make 1 half double crochet
Into the next 2 double crochets
Into the next 3 treble crochets
Then make 1 half double crochet, 1 double crochet and 2 treble crochets into the next crochet
Put another slip stich into the last crochet and your heart is finished.
You can now crochet some chains to be able to hang it up. I used 10 chains and then did another slip stich into the same crochet as the first to make a little loop.
I used my hearts to make a sort of a 'prayer tree', hanging them on a branch and attaching little messages of goodwill that will hopefully filter through and help restore calm in our household :-)