I first put my grass clippings in an existing compost pile. I mix them around and get them somewhat converted to actual compost/dirt before I put them on any of my plants or in my garden. I have found that grass sometimes gets clumpy, moldy, and doesn't decompose as well without several turns, and I don't want to be upsetting the roots or risking damage to the plants doing any turning. So, getting it started in a separate area, then transferring it over when I know it is ready has been a winner for me.
I have a couple plastic trash cans with lids, I drilled 1/2" holes all around the sides for some air flow. I fill that with leaves and grass clippings and some compost, a little water. Every few days I lay I them on their sides and roll them around, put some more water in there. If I come across any worms, I'll throw them in there too. The speed to get grass clippings turned into excellent compost dirt has been twice as fast as a compost pile.