I am the dump one who says to his customers that their prices will NEVER be increased.
Now you might think I'm mad, but it does work.
I look at my monthly turnover figure and profit margin and convert this down to my hourly turnover rate, to judge whether it works.
When I first started I had a hourly rate of £33 it's now £41.
Now the secret to it, have a look at your round, does it stay the same all year around, you will find that it doesn't.
You will lose some customers, and you will gain some.
At first you need to make sure that all your customers price are achieving your monthly and hourly rate, if any need to be increased then do so, if its by more than £1 per clean, then raise them in stages, the 1st of Janruary is a good date.
You now need to set the rate for new customers, this is always higher than what your current customers are paying, I normally charge £2 per clean more.
The next part is easier, re-orginise your round and what equipment you use, for instance mix some higher priced work with your lower priced jobs.
Also you will find that a backpack is faster on some jobs than the trolley or van mount is, and vise versa.
If you don;t have these systems then get them because they will make you money.
It really is not rocket science, for the last 4 years, my turnover has increased each year and I have a very healthy profit margin.