I have a TP Link WR702N nano router, which I bought a few years ago to use as a repeater. I no longer need it for that so decided to try it for the first time in Client mode this week - and it works with my A1200!
Briefly, this means it acts as a wireless receiver, and simply comments to any wired ethernet port via RJ-45 cable. I've not had to make any further changes to the Amiga beyond the wired network setup I already have.
Routers with client modes can be found quite easily and cheaply, are more readily available than wireless PCMCIA cards for those of us with A600s or A1200s and definitely an easy solution for big box Amigas.
To be absolutely clear, this only works if you have a working wired ethernet set up.