Some people are just takers. They see it like a bowl of sugar or a mug of milk is neither here nor there. It doesn't cost you much and you have it available. Same goes for a lend of something. It's not like they're keeping it, right? You'll get it back when they're done! 
Same with getting a lift too. It's not much to give someone a ride, right? It only takes a few minutes and you have a car anyway that was just sat there.
But it's fucking annoying. It comes to the point when your phone pings and you see your neighbour's name and you think, "Fucking hell! What do I need to do now?!?!" And then you hide your phone pretending you never saw the message and spend the time waiting for them to knock instead while thinking of various possible reasons to say no to whatever it is.
I'm going through similar OP. My phone is constantly going off with requests for lifts or a lend of XX or XX item. It was my sweeping brush every time it was time to do their floors. My weighing scales when they were following a recipe or my wok when making something too big for their frying pan. There has been cling film requests every other night for a week or two until they bothered buying their own. Milk, sugar, butter and bread were normal requests. Now these aren't people just starting out. They've lived there 30 years and even have an adult daughter who lives at the end of the street. She never gets asked for a lift or supplies but come every hairdressing appointment, doctors or just a lift to the corner shop because it's pouring down I'm getting knocks or messages. Neighbour even asks me to pick them up from the train station a couple of streets away. Yeah it may only be a minute in the car to him but add that to the time (and even just effort) it takes me to stop what I'm doing, get my coat and shoes on, get the car key, lock the front door, drive round, find a parking spot and then wait for however long it takes for the fucking train to arrive!!!
I understand how this has happened @Missymisenthrope . You start out being kind, thinking, it's a one off. It's fine. It's no loss to you. And before you know it you're getting told what you need to do.
I got the balls to pull right back when the messages turned from "is there any chance you could possibly please?" To an outright "listen, I'm going to need you to....". Fuck that right off. OP, get a list of excuses together if you don't want to let their fucking cheek lead to friction. Ease back. Increase the no's with an excuse from once every few times to regular refusals until they stop asking. I've trained mine down to one request a week from dozens. They're getting there. I don't give excuses now either.
It is absolutely not your fault if CFers don't like the no they get and MN would have you telling them to fuck off but if you want to keep the peace and not be on bad terms, gently gently is the way to go. A fall out WOULD be their doing and they certainly would be in the wrong, but do YOU want that hassle?