I use a local wi-fi outlet, the public library. It is about 200metres from my place and I use a Digitech hi-power extender to help me. Generally I get three bars on the signal but sometimes the signal is too weak, showing two bars. The extender hangs upside down pinned to a window curtain behind the computer.
Recently I've been trying to improve the signal and had a look at a few ideas using silver foil on youtube. I tried most of them without success. then suddenly had an idea and pinned an old aluminium pie dish (nicked from the kitchen) over it. The result was excellent and I got four bars on the signal. Had to return the pie dish so went round to the local opshop and bought a stainless tray for $1.
Glued some pegs to it and pinned it over the extender. The results are excellent and I now get good signals day and night.
Have a look at my efforts!!