Clumps of Tall Grass
I wanted some tall grass clumps mainly for my Africa settings but these are very versatile and can be used almost anywhere.
This is scatter terrain that can be added to river banks, forests, swamps or whatever so I wanted lots of small bases rather than a few large ones. I cut my bases out of some 3mm flexible cork tile. The cork isn't the type I use for buildings, it has a much more pronounced texture on its rough side which saves on basing material later.
I cut he tile with scissors and got 16 bases out of a 30cm square tile which made each base about 60mm across.
At this point I could have sanded the edges down but it would have added quite a bit of time and mess so I didn't bother. ​

For the grass itself I bought a broom off eBay for under £8.00. That gives a cost for the 16 bases of grass here of £0.50 each even if I don't use the broom bristles for anything else. This little project hasn't used much of the broom at all.

I used hot glue to stick the clumps of different length bristles to the cork. This is what took the time but, even with waiting for the glue to set enough to allow me to move on to the next base, the whole process only took about an hour.
I used a production line process, sticking a tall clump in the centre of each base and then coming back and working around these adding shorter clumps; one clump per base then moving on to the next to allow the early ones to set fully before it was their turn again. 

Once they were all set I painted the bases with my standard base colour and added just enough basing compound to cover the smooth hot glue and allow me to sprinkle some grit for extra texture.

Once everything was dry (I left them over night) I dry brushed the bases with my two basing colours so they matched everything else and they were done.