I used a size US size 6 steel (1.9 mm) crochet hook and size 10 cotton crochet thread.
Finished size 6 inches (15.24 mm)

US terms
Sp/sp-------------space or loop
Dtr/dtr-----------double crochet
Ch/ch------------chain
Dc/dc------------double crochet
Hdc/hdc---------half double crochet
p/picot---------- ch 5, sl st in last sc
Tr/tr-------------Treble Crochet
cluster st: (thread over hook twice, insert in space, pull through and work off 2 loops twice,* thread over hook twice, insert in same space, pull through and work off 2 loops twice, repeat from * once, thread over and pull through all loops at one time)

UK terms
Ss/ss -------------space or loop
Dtr/dtr----------double treble crochet
Ch/ch------------chain
Dc/dc------------double crochet
Htr/htr----------half treble crochet
p/picot-----------ch 5, ss in last dc
tr/tr--------------treble crochet
cluster st: thread over hook twice, insert in space, pull through and work off 2 loops twice,* thread over hook twice, insert in same space, pull through and work off 2 loops twice, repeat from * once, thread over and pull through all loops at one time