craft, the best way to get rid of dandelions is to put a small heap, quarter to half a teaspoon in the centre of each and just leave them to die, it won't hurt the grass, its cheap and it works.
I am still working on the bindweed and grounds elder with roundup gel so early days yet.
I've sorted out the bindweed by putting a cane near the plant & allow to climb the cane, then I duff it up with round up....They use this method in Kew gardens.
Helen Yemm suggests just adding some wallpaper paste to normal roundup, and apply with a small painbrush, it has the same effect. I am going to give it a try!