First thing to do is to know the rules in the area your host lives in about RV driveway camping. More and more communities are passing anti-RV ordinances, and some of the more restrictive may affect how you operate. Google around and check the municipal and county ordinances for your destination before you get there. The most restrictive, like Monterrey County in California, flat out ban sleeping in a vehicle. They don't care whose vehicle it is or where it's parked – you can't even sleep in your vehicle in your own driveway. Others, like Sarasota County in Florida, ban electrical hookups except for a few hours before departure. And, of course, there are homeowner association rules, most of which are decidedly unfriendly to RVs.
Don't bring aggravation or the disapproval of neighbors down on your host by breaking these rules, and be discreet if you are bending them a bit. Try to look like you're parked, if parking is all that's allowed. Limit inside lights, TV use, lots of coming and going, obvious water and electrical hookups, etc. Pretend like you're operating under the scrutiny of nosy neighbors who love to complain, because you frequently are.
If the driveway itself is too crowded to park on, remember that you are a large and heavy vehicle, and move it every few days to give the lawn a break. Right now I am at my sister's house, and the designated lawn parking spot had taken a beating from frequent use by many vehicles before I arrived. After using it a few days I moved over a few feet, grabbed some garden tools, aerated the packed down soil, and resprigged the area with grass, which I'm watering and fertilizing. I don't recommend this course of action for everyone, because you know how fussy those sticks and bricks people are about their lawns, but a a minimum communicate with your host about their preferences for where it's most convenient for you to park, and at least offer to move around if you are on grass and staying more than a few days.
What to bring inside? As a general rule, we only bring stuff inside for immediate use, and take it back out to our Roadtrek once finished. We usually pack our shower stuff in and out every time we use them – same with changes of clothes. Food is a little different; I'll bring stuff in to cook, but avoid leaving a mess in the kitchen or crowding the refrigerator with stuff not being used immediately. You have a perfectly good refrigerator and stove outside that they aren't cluttering up – return the favor. Also, be alert to the customary times your hosts use the cooking and bath facilities, and learn to work around them.
What I do with family is chip in on utility bills when I am staying for several weeks. These poor sticks and bricks people get an unpleasant surprise every month in the mailbox called a utility bill, and to be fair if you're using the shower and electricity at their house, some of that expense is yours. I usually just split it per person and don't worry about who's using what – the nice thing for me is I'm driving away soon, and my only “utility bill” will be a few bucks for propane once every few weeks, whereas they are going to be stuck here paying these utility bills year in and year out. Help them out a bit and cover your portion.
That's what I do to be a good driveway camping guest, and nobody's kicked me out yet, except a couple of my in-laws, but that was probably for reasons that had nothing to do with my driveway camping etiquette. You just never can tell with some of those people…