I thought I'd try 'Grass'. Its what every art student does at one point.

(Was a Joke.Worked if you laughed)


OK. I needed to do this as my scene is set in a park... and how many modern parks don't have grass? Not many. So; using the 'hair and fur (WSM)' tool it started off OK. I found the longer the strand of grass the better it looks.. as it fills more of the gaps in between the individual hairs. It started off at around 3000 hair count.
Finished at 72,000. (render time difference was nothing on 64-bit so I don't know why I was so scared about it)
Another thing I learnt was displacement and the mutant variations add great detail and depth into believably. Essential in other words. So is lighting as it adds shadows to the hairs.
The above image shows my first scene without lighting or effects and when my hair count was very low. Left and below are my finished renders that showcase the difference. I particularly like the softer feel of the later variations.
Have a look. Have a go yourself. Fairly easy.