I have an Aunt that has the best grape vines I have every seen and they are 99% maintenance free. She has 4 wooden posts in the ground they are spaced 6 ft by 10 ft apart in a rectangle shape with a post at each corner of the rectangle. The post stick out of the ground about 6 1/2 ft high. There are board running between the post to form a box shape. There are several boards running across the 6 ft width they are 2 ft apart. There is some fence wire laying on top. The fence wire has small square about 2" by 4". There are grape vines planted at each corner at each post. The vines grow up the post and across the fence wire on top. The grapes are heavy and they fall through the holes and hang down under the bottom side of the fence. When you want to pick grapes you simply walk under the grape vines and the grapes and just hanging there above your head. They are very easy to see and very easy to pick. The only maintenance my Aunt ever has to do is trim the vines shorter when they get too long and start growing over the edges and hand down the sides. My Aunt gets several bushel baskets of grapes every year. She has red and green grapes growing together, they get ripe and they taste very good to me.
I have a neighbor that grows grapes for wine. He has 4" wood post in the ground in rows with 3 wires running between the posts. There is a 1/8" steel wire at the 6 ft level, 4 ft level and 2 ft level. He has grape vines planted about 8 ft apart. He has trained the vines to grow on the wires. It is a lot of work he is out there a couple times every week checking the vines to make sure they grow on the wires parallel to the ground. He has to trim the unwanted part of the vines and tie up the vines he wants to keep. The grapes hang down under the wires. He gets some nice looking grapes but it is a lot more work than what my Aunt does and he gets less grapes than my Aunt. My neighbor grows only green grapes for white wine they taste good too.
Thats about all I know about grapes other than they need full sun and plenty of water. According to everything I read my neighbor is doing every thing right and my Aunt is doing every thing wrong.