I can suggest, but the rest of world and even Europe is quite behind on what we in the UK would consider is minimal safety when it comes to electrical installations. We are supposed to be "harmonised" with Europe like 15 years ago but the only thing that's the same is the colours and sort or the voltage but not fully. So there may be things that are harder to get but I will try.
Couple of key fundamental things:
Use plastic back boxes everywhere, so "fast fix boxes" or plaster board boxes. Three reasons for this, the minimum depth of them is 35mm and the deeper the box the better if you can use 47mm it really opens up options. The other reason is most devices are wireless so signal is not then put in a Faraday cage like it is when using metal back boxes. And also allows you to make changes easier as you can leave a little slack in the wall.
Everything should have a live and neutral at each point. Most devices need a feed of some sort so by ensuring you "loop down" to each switch location for example it again opens up much more options and doors on you journey.
For best practices in our regs there should always be a point of isolation within a certain distance to the device, that could be as simple as a light switch isolating a lamp or light fitting (with lamps) in a room (yes it's a lamp not a "bulb" they make flowers ). So what do you do when you switch is smart? Should that be isolated locally? As a sparky I would say as per the regs you should not remove the cover when the supply is live so no because you should isolate the whole circuit. However if your changing the lamp on that smart switch is it isolated when you turn it off? No mostly definitely not, so how I get over this is each room has a "key switch" isolation point at high level (2 m ish) this cuts the light supply to the room and so is compliant.
All over device ie power are already have normal isolation points in the room or blinds (on the socket's circuit) has a un-swiched isolation point to fuse it down EX.
All of this has additional advantages to smart home aswell, it means when your settings up or joining device you can isolate per area. So resetting a smart lamp for example doesn't reset the whole circuit.
A new addition to our regs is surge and ark fault protection and this again is something which is advantageous for a smart home protecting your devices and you.
RCBOs per circuit is also a min requirement in the UK (not that everyone quite abides to this one, most have two RCDs which is understood to be acceptable, but is technically against regs).
The reason for these suggestions is for example smart switches modules they can be used with normal dumb looking switches. This again brings down costs as it opens up options. There are loads of manufactures who do these I'll try and update this with some links once I get to my PC .