Pokeradar Problems

I've just recently started shiny hunting. So far it's been great and I've gotten 20 or so shinies in the past week from various methods.

However, I cannot seem to get the hang of pokeradar to save my life. I've watched multiple how-to videos, and read several guides, but no matter how hard I try my chain always gets broken. The highest I've ever gotten is around 20.

I know the basics, and which grasses to go into. And to avoid any on the edge. My main problem seems to be when there are multiple grasses that match the criteria (large, loud, violent shaking). What do I do in this instance? That seems to be the one thing that is holding me back and breaking my chain most constantly. I've read that if there is more than one grass that you should go for the farthest one, however time and again it has shown me it is not the case.

So, to those who have more experience than me in pokeradar chaining, what am I doing wrong? Should I just keep resetting in the instance of multiple 'good' grasses til there is only one or is there some magic piece to the puzzle I'm missing? (and any other tips would be greatly appreciated) I've been trying for several days to get a shiny Bunnelby, but I just can't keep a chain :/