My usual is NEVER more than one router. I will use a router as a WAP but given the troubles of more than one router, not a setup I will support.

That said I place the router IP at easy to find addresses so I can manage them but never at the lower number. So let's say my LAN is 192.169.0.x/24. I'll let my router be at the .1 location. My other router as a WAP will be out at .200, .201 and so on. My WiFi DHCP range may be .100 to .199 and the wired will fall in the .2 to .99 range.

If you are implementing BRIDGEs then those can be up with the 200 range and you sketch it out plus lable it all for later management.