For those that have never tried it it's also worth it just to understand more deeply how amazing these cheap devices are. For ~100$/€ you get a single board computer, plus a managed switch, plus 1 or 2 wifi cards. The managed switch in particular is very interesting. The computer is just another connection to the managed switch and you can configure it in any way you want. Traffic can go directly from one port to another without going through the CPU.
These capabilities together make a network of OpenWRT devices really flexible. I use it to replace the included router from our Internet/TV/Phone provider. The VLANs are needed to access the different IP networks for the different services. That you could do with a normal network card but then I also use VLANs inside the house wiring to take the IPTV network to the TV box. I then use a separate SSID to carry that VLAN in a point-to-point connection to another OpenWRT AP as a client so I don't have to run wire to that place and so the broadcast traffic doesn't swamp other normal Wifi clients. All this can be done with these very cheap devices that already have all the needed hardware. For all the deserved fame RaspberryPI gets these routers are equally amazing hardware for a lot of things.