I send out monthly one page newsletter to the HOA/POA communities I service. We normally just send a couple of the employees around at the end of the day to hang them on the doors. I use one page front, glossy heavy bond, copy them at Office Depot from my proof (black and white). This has a great response from the homeowners, it is mainly a tool to keep them informed of our planned work...this really works to our advantage especially when we need to keep the home gardeners aware of fert, pest control, etc so they don't double up.
I also advertise in the HOA/POA community papers. It is very cheap...the most expensive is 33.00/month and reaches about 900 homeowners. I find this good for PR / politics / extra business. It has landed me some landscaping jobs and regular property detailing for some of the HOA's that I do not yet have as an account. There is nothing like having an HOA board member unload about all the problems with the current maintenance company to the competition!!!....and having them pay me directly to fix all the problems on a monthly basis. Now I'm planning my next marketing and sales strategy to target these HOA's for annual contracts.