modelling with billboard planes

Hi, Im looking to make a very low poly model or use billboard planes to achieve a simple grass on an object i can use for a IOS/Android game for my uni project.

Ive read into methods about combining meshes to reduce draw calls etc in games so i want to model my grass so i can make it into one object. I know the professionals use billboard planes to achieve this. The attached image is roughly how i want the grass to look (not flat but a little 3d) i know there area numerous ways and just wanted pointing in the right direction. Theres not alot of information which is understandable to me out there.

attached is an example billboard grass and the other image is the end result (ideally)



Any advice regarding making this and be good enough for mobile games would be great!

Or could the 3d effect be achieved using bump maps?

cheers

Nick