How do I makeover a garden that has had grass removed?

Cement. Gravel will not keep out the weeds. If you are talking about a plant garden, dig up all the grass roots then put down at least a 3 inch layer of mulch.

Are you wanting to put in a flower or veggie garden, or do you want to just put something down where you are going to remove the grass? If you want to put in a garden, you will have to amend the top soil so that the soil is good for planting. I always do the same thing to areas that I start as gardens, I till in potting soil, peat moss and sterilized manure at a mixture of two potting soil to one peat moss and one manure. I have always had good luck with that mixture in new gardens to enrich the soil verses just using the top soil that was under the grass. I had a great neighbor that coached me on my first veggie garden and even let me use his tiller when he found out I wanted to put one in the back yard. I had so many veggies in my garden that my oldest son would take bags of veggies in his wagon around the block to give to neighbors! I use shredded leaves and cut grass for mulch and till that in every spring when I am ready to replant. Some use wood mulch which will still put nutrients back into the soil, with a layer of garden fabric underneath it. I don't like using stones or gravel, as unless you put up a barrier that is above ground level, they will migrate out of the garden. Mine is slightly hilled and gravity will move them down when it rains and I would always have to be moving it back up. I hope this helped you some, Chris!

grass roots are extensive & deep you need to rototill ground down about 8" to remove all the roots or you will always have grass growing Depends what you want,gravel,cement,decking,gardens with walkways,pool,mulch(wood or rubber) what do you want to use yard for?

Depends on how you want to use the area. Entertaining? Look into Xeriscaping.