Nice skippers. You've nailed the focus in these - the eyes.
I pretty much have my 1:1 macro lens set at f/11 and leave it there. Only open it up if I'm shooting at higher magnifications with tubes or the MP-E 65 to control the diffraction softening.
Particularly if it's windy you did the right thing and keep that shutter speed up around 1/200s. Good choice.
ISO I play with a bit to get the background exposure to within a stop or 2 underexposed. Just so it's not pitch black, but the subject will still be lit and stand out while at the same time keeping the ISO down for noise control. If that all makes sense...
Diffusion - you could get a
ready-made softbox like this one pretty cheap. No need for DIY or flash brackets etc.
DDP have them.
I'm in the process of putting on my webpage a bunch of things I've picked up along the way shooting macro. Not ready yet, but I'll let you know when I do if you think it'll help.
Man, all you guys shooting macro, spring is here, I gotta get out there!