Dazmond
To achieve higher prices than your compitition you need to offer your customers a better quality of service than they do.
The following are some good pointers.
If you are a trad cleaners always use fresh water on their house, not what you have used on their neighbours.
Telephone the night before, if they say they won't be in and they cannot leave the gate open or you need to access the back though their property, ask them when the right time for them will be, say you work you round around them, it makes them feel special and its not really putting you out to much because all the customers will not ask you to do this.
I always clean the frames and sills on every clean, I also clean the front and back doors, but where I differ from other cleaners is I will also rinse down the facia boards - gutters and downpipes if the are dirty or green, the same applies to the garage doors if the are white. ( a house with clean windows does not look right if the downpipes - facia boards and garage door are minging and it only takes a few minutes).
Dress and be clean shaven and a profession image.
I always give cards and gifts (pen) at christmas.
Don't be scared to charge high, have confidence in what you do and your price will be justified.