I don't currently have a six-month-old, but I can tell you what I've done with those I did have, including those I provided childcare to.
I'm a fan of bottle-fed babies that age having a bottle when they wake up, kind of a snuggly welcome to the day.
An hour or so later, breakfast. I'd offer mashed banana or another mashed fruit, and oatmeal or another mushy grain cereal, and a sippy cup of water to wash down the food between bites. (I never use baby food, but you can buy in baby-food form everything I'm suggesting, so whichever way is better for you.)
Lunch and supper, I'd offer mashed fruit or vegetable, and a mushy grain (like rice with formula or juice blended smooth). Again, a sippy cup of water just to wash down bites.
Depending on the child, I'd offer formula either just before they took naps or just when they woke up, whichever seemed to make the child more comfortable.
As far as the amounts I fed them, well, I fed them formula based completely on what amount the doctor said to offer. With the other food, I let the child choose how much to eat. It's not easy to overfeed a six-month old as long as you offer only healthy foods and follow the doctor's instructions regarding how much formula to offer.
A baby's little body knows when it's time to eat more than normal because of an upcoming growth spurt, or eat less than normal for some reason. I've never once raised or provided child-care for a baby who became overweight or underweight, and I fed them all the way I just described.
Oh, two things - when I write "doctor" I mean whatever health care professional is the baby's primary. And the reason for the sippy cup of water is because it's an easy way to introduce a new skill, and it gets the baby used to the taste (or lack thereof) of water, so that a year from now, s/he'll be comfortable drinking water instead of juice or something sugary on summer days.