Clothing? Yes, Hi-Viz is good if a little “Mr. Safety” looking. Personally, I’m past caring if I look “cool” or not and have one of these for Winter commuting:
http://www.whitehorsepress.com/product_info.php?products_id=2360
I did detect a snicker once from a Harley rider who works with me, but better to look stupid than dead I reckon; others apparently disagree with me on that one though.
On my last bike I had a headlamp modulator on my main beam and that really used to do a great job when lane-splitting. Many cars (probably initially thinking I was a cop) would make a wide-berth for me when they saw me coming. It was like Moses parting the Red Sea Woe betide any motorcyclist lane-splitting in the next lane though!!
BTW: If you’re going to lane-split (legal or not), please do so in the leftmost lane (in LHD countries); it’s much safer for all concerned (as much as lane-splitting is ever “safe”).
That said though, I eventually took the headlamp flasher off as on more than a couple of occasions, I had the distinct impression that people would pull out in front of me as they thought I’d signalled to them to come out (even though it would be flashing constantly, multiple times a second). On the other hand, maybe they were just plonkers. Whatever !
I had one of these (below) on my last bike too. It seems to work well and being separate from your stop light should be legal anywhere I would have thought:
http://www.whitehorsepress.com/product_info.php?products_id=5125
How you position yourself in the lane can also help greatly with visibility and never ride 9 feet behind a van or truck (or any vehicle come to that) like I see so many doing. For one thing, no-one can see you and for another, you can’t see anything of what’s happening on the road in front of the van or truck. In my newbie days, I came within inches of a rear-end collision on a number of occasions when the van in front suddenly stomped on the brakes.
I just never saw it coming.
Anyway, that’s all I’ve got to say for now.