My best recommendation would be to work on three things this coming year...
1. Hit up the Kindergarten parents. These guys are a resource just waiting to be tapped. Think about it, many of them are excited, and maybe a bit hesitant, of their first born starting their elementary career. Many of them want to get involved, but don't know how. Now many some of them will ask about getting involved and may even show up to a PTO meeting. Of those few some may come back to another meeting. But unless you get them engaged you'll lose their interest quickly.
2. Make you PTO fun. My first year as PTO President a couple of years ago I started a new tradition of a Back to School Ice Cream Party. We run it the day before the first day of school and promote it as a FREE "meet your child's teacher" event. We've even gone so far as to invite the mayor, local political figures, the Superintendant of Schools, etc. We try to hold it outside, and have music, prizes, games, ice cream, etc.
I have a PTO information table and have articles from PTOtoday about involvement. I allow the parents to take from the table as I find the less saleslike the information is the better.
I include an e-mail sign-up list for PTO information, which includes PTO meeting invites, event information, etc.
3. Communication. Not sure what your group is doing in this regard, but when I took on the role of President I found that this was an area that my groups was very weak in. The previous year they had one newsletter go home throughout the entire school year. The PTO portion of the website was a single picture of the old playground, which had been replaced by the PTO 2 years earlier. I decided that this would be one of my priorities for the year. I created a brand new PTO website, which information about our events, fundraisers, getting involved, spirit items, parent resource sites, our caladar, pictures of our events, and much more. I created a monthly, color newsletter thaat discuuses all of our past and upcoming events. These things got the word out so that anybody who wanted to would know how to get involved.
Here we are two years later and the active membership has increased from about 8 - 10 to over 40, including a male active involvement increase from zero to five or 6.
Hope these ideas help,
PresidentJim