OK - this is a very broad question! What techniques and tricks can I use to help to produce flattering imagery in a run-and-gun situation?

I don't have a huge amount of experience with filters although I'm fairly certain that I don't want the 1/8 pro-mist look because it's just a little too... um... cheesy. So I'm thinking that I'll shoot without any diffusion and maybe add a tiny touch of diffusion in post. Or are there any filters which just take the edge off facial imperfections without looking too much like 1980's porn?

I'm planning to shoot on a Panasonic GH1 with Nikon prime lenses because I love the shallow DOF on portrait shots. I'm not sure if the GH1 has a setting for sharpening but if it does then I'll turn sharpening to zero (after doing some tests). I was considering buying an LED ring light but they seem to get poor reviews and cost the earth. Instead I'll try to position a reflector really close to the camera (pointing towards the subject) to try to soften any shadows.

I'll shoot from a slightly higher position than the subject's eyes so the camera is just slightly looking down at the subject to help to de-emphasise any flab under the subject's chin.

Where possible, I will try to light the subjects but that wont always be possible.

Any other tips and tricks???

Hmm... the Kino Flo Kamio 6e ring light looks very nice. I wonder if there's a way to mount the 6e to my rails and/or to my Red Rock mattebox.

Some of the Sony cams have a 'soft skin tone' setting that detects skin colours and softens that part of the image. I've never used it personally on my FX7 but perhaps the GH1 has something similar?

Some of the Sony cams have a 'soft skin tone' setting that detects skin colours and softens that part of the image. I've never used it personally on my FX7 but perhaps the GH1 has something similar?

If you're planning on using older Nikkors, the f1.8 50mm AI-s Nikkor I just got for the same purpose on my Canon T1i gives me SUPER SHALLOW DOF at 1.8 in soft daylight and the lens itself at 1.8 looks noticeably softer than the Canon EF 50mm f1.8 left over from my EOS 650's (the first film EOS they put out).

It looks like that 50mm Nikkor is going to give me just the right amount of gentle softening at 1.8 for my taste.