I struggle with indicating on the bike - particularly going right. I want to get better at it, but a year or so ago I came off while indicating right and broke a couple of ribs so I've lost all confidence, particularly if I need to brake at any point during the manouevre. But, at least I know that I should be indicating, and I do other things instead - trying to get eye contact when I look behind me, positioning myself assertively approaching the junction to prevent people trying to squeeze past and so on.
I did get wound up once when I needed to change lanes in the lead up to some traffic lights which were (a) red and (b) at the bottom of a hill, meaning that not braking wasn't really an option. I made eye contact, the driver in the lane I was moving into clearly knew what I was trying to do as he left room for me. I moved into the space, all nice and smooth... then the driver who had been behind me in my lane pulled up alongside and had a real rant at me.
On the flip side I've lost count of the number of times recently that a driver has pulled away from the side of the road as I'm alongside them without indicating.