I main support.
I always get the role I want.
I fill.
Just make your main support champ Bard. Then watch how fast someone else steps up to play support. Of course, you can't mention it until AFTER the bans.
The sad thing is that you should get mid or top for last pick so you can counterpick, but it's YOLO Q.
I prefer last pick because no one else seems to give a crap about team comp synergy. If I pick first my team never has any synergy (like 3 AD assassins and an adc), at least when I'm last pick I know I can bring a little synergy to my team.
Doesn't happen as often as it used to lately. With me at least. I just write "jg pref" and I it get often even when last pick.