I use home assistant automation to unlock my door and disarm my alarm, with the following security measures:
If someone get my iphone, they still face id to open home assistant app.
My latest is to better manage my heat tape. I only want them to run 10 am - 4 pm when the temperature is below 32F and if itās been 24 hours (still working to optimize that time frame to base it on how long the conditions were āsnowyā and or figuring out where to get total snowfall) since the end of the last snowfall. Already saving me $100ās over the old turn on/off manually at start/end of storm or even worse on in the fall / off in the springā¦
For me honestly I use home assistant as a backup for when internet down. My most useful automations are probably:
Phillips hue hub with Phillips hue lights.
Sometimes hub wonāt turn on/off lights properly with sunset/sunrise so I have home assistant making sure it does.
For my office and kitchen I use Lutron casetta, my kitchen and office lights are dimmable with toggled tube lights. This works flawlessly and gives me proper lighting in those 2 spaces. I only wish I could change colors of tube lights but looks so professional and clean. Probably add their motion detector to turn on office lights anytime I enter shortly.
Lutron casetta outdoor plug for switching between grid and solar in my basement. I started off with cheap plugs like tp-link but found them very unreliable. I usually automate with python discharging my solar batteries each night to let new sun into them. This is custom in a cronjob, I read battery voltage from victron solar charge controller then turn on/off Lutron plug based on that voltage which I update voltage every season.
I started with all the cheap light bulbs, cheap smart plugs, but I found going reputable more expensive brands has given me flawless operation and no issues like the cheap devices when it matters like dealing with your solar setup etc. Casetta line no issues, might even do their smart shades at some point. I think if you want to up the value of your house, anything you do with Lutron casetta will do exactly that.
If internet goes down I can ask Nabu to operate my devices with their voice assistant. I virtualized home assistant under freebsd vm-bhyve on my server so it has very powerful hardware to work with and take regular zfs snapshots of all the VMs just in case.
So when I think of automating something, I think if I ever sold this house, I could leave behind Lutron hub etc for them and they good to go.
Iāve done most things myself, other times I called an electrician if I was unsure about something like getting toggled tube lights dimmable with extra wire etc. Didnāt want to crawl around in attic anyways 
Iāve run fiber optic from cheap QNAP switch in basement to QNAP switches in office and livingroom along with 12/2 wire from triplite grid/solar redundancy switch, same they use in datacenters to my livingroom and office, power goes out, does not interrupt me on ps5 or my PC.
Keep in mind I never started off even wanting to do solar, I just wanted a battery backup for good amount of hours if grid failed where my electronics were unaffected. Then I thought why not get a solar charge controller and toss some solar panels outside so I can charge batteries for free instead, works out great. Just donāt get those hybrid inverters, a good giandel inverter, feeding into a data center grade triplite off eBay will give you those sub 2ms switching times. You donāt need any expensive victron equipment, only part I would is their solar charge controllers, their app rocks. I just feed a serial cable from my server into it to pull voltage of battery.
Better than my first cheap ass setup, modified UPS hooked up to 2 car batteries lol, a bunch of Will Prowse YouTube videos and sourcing my lifepov4 batteries directly from Alibaba later, so much cleaner setup and batteries will actually last 10+ years.
For a cleaner look plan on hiring an electrician again at some point and install proper wall outlets for the 12/2 wire and the fiber optics. At least this way gives you upgrade path from 10gb to 100gb just changing out the switches and transceivers easily since Iāll run om5 fiber.
So I think things like fiber runs with professional wall plating, custom solar/grid outlets, Lutron casetta of anything that doesnāt use third party cloud providers is probably your best investment, maybe you could leave behind a cheap mini PC with home assistant on it and a Nabu voice assistant to with all your other automations with zwave/ZigBee to.
Avoid using device_id like that. Use named entities only
My automations:
My most usefull automations are that I get a push notification when the flap of letterbox is opened. I live in an apartment so itās useful that I know it when the post is brought.
The second is that my windowblinds are automatically closed 30 minutes after sunset.
We have a Zigbee wall control for the IKEA colour temperature dimmable smart lights in our kitchen/diner, which are also controlled by the Adaptive Lighting integration.
The four scene buttons are designed to recall a Zigbee scene for one of the four groups of lights bound to the control, but this requires pressing one of the number buttons then the scene. Generally we just want to recall a scene for the whole space, so we ended up having to press 1, 2, 3, 4 then the scene button.
I therefore got rid of the Zigbee scenes and wrote an automation that listens for the button presses:
Not rocket science but really useful because we use that controller several times a day.
Not a single automation, but I like our automations around sleeping/waking.
Closing our daughterās bedroom door at a particular time of day turns her input boolean helper on. This in turn dims the light outside her door (using Adaptive Lighting āsleep modeā. If we open the door in the night time for any reason, the light will stay on even if motion isnāt detected on the landing, so that weāre not plunged into darkness in her room.
When we go into our bedroom in the evening, the motion sensor turns our bedside lamps on at 40%. My wife and I each have an IKEA remote on our bedside tables to press when we go to sleep, triggering an input boolean helper each. If one of us presses our sleep button, our bedside lamp turns off and the other one dims to 1%. If one of us is out and the other presses the sleep button, the lamps turn off.
When either adult is sleeping, the (motion-activated, adaptive brightness) hall light will only turn on very dimly (Adaptive Lighting āsleep modeā) to avoid light spill into the bedroom.
When weāre both asleep, a script runs to do all the usual turning things off. It also closes some blinds if the first sleeper hasnāt been asleep for a while (because we donāt want to disturb the other with the noise).
Turning our iPhone alarms off in the morning turns the relevant boolean helper off (via an iPhone automation that runs a script), turns our bedroom lamps on if itās dark and opens the kitchen blinds if itās light enough.
Simple, but playing stuff on our TV in the evening dims the lights, and turning the TV power off after a certain time brings the lights back up a bit. Just avoids having to reach for the dimmer switch!