If you just want to prevent opporitunistic break ins then you just need to make your house a less appealing target than the neighbors. A sturdy door, motion activated lights, and a dog can do that easily enough. If you want to go the extra mile then put up a few cameras. The cameras don’t even need to be real. I used to work for a fortune 500 company that made extensive use of fake cameras on their properties. The trick there was that they also had a few identical looking real cameras as well so unless you had insider knowledge, you would have to consider all of the cameras real.

Now if you want to stop someone who is determined to break into your house specifically then that gets trickier. You will never stop someone determined enough so the goal is to just make the process of breaking in as noisy and difficult as possible. You will want a good and properly mounted deadbolt on all your doors. By properly mounted I mean, throw out those dinky 1" screws that came with the deadbolt plate and mount that plate with some big old 4" long screws. A deadbolt plate just screwed into the doorframe does little good. But if you screw that thing clear through the door frame and into the (preferably doubled up) stud behind it, then bashing in your door goes from requiring a swift kick to requiring a ram or a sledge. Also, if you don’t like the look of bars on your windows, you can just apply huricane laminate to your windows instead. It’s a film that is designed to be applied to windows in huricane prone areas to prevent debris from flying through the windows. It also makes smashing in your windows a tremendous pain in the ass. The glass will still break but it will all be held in place by the film similar to a broken car windshield. It is possible to get through but it is a very time consuming and conspicuous process. Finally, cameras. Now that you’ve made it a pain to get through your doors and windows, you want to be sure that anyone who would still be willing to put in the effort also knows that they’re being watched the entire time they’re breaking in. Yes you can still smash in a door with a proper deadbolt or smash in a laminated window but few people are willing to spend that much time on camera being recorded committing a crime. Beyond those measures your walls become the weak point and there isn’t much you can do about that without rebuilding the house.