My first SBS so go easy on me. Also colour balance is a bit rubbish.
Thread – Olive Powersilk
Hook – TMC200R size 16
Abdomen – Clear larval lace or similar (I use 0.5mm Stretch Magic – much cheaper)
Hackle – to suit
Thorax – yellow closed cell foam
wrap on thread
tie in a length of lace
wind on lace in touching turns and tie off – to get a nice taper stretch the lace for the first turn or two and then gradually ease the tension as you wrap
tie in hackle – note short length of stripped hackle
tie in a length of closed cell foam cut to approx 1mm x 1mm
wind hackle around foam as if you were tying a parachute - lots of turns 6 or 7 maybe
tie off hackle and pull foam forward and tie off – it helps to sweep the hackle back with finger and thumb as you pull foam forward. Be careful not to cut through the foam with the thread
instead of lace you can also use quills etc.

a bit messy, but you get the general idea I hope.
I've also tied this without the foam and used the tied off lace as a 'post' to wrap the hackle round.