As always, PV should be low on your priority list. I'm guessing you've already done this, but for all of us:
Make all of your appliances, heating, cooling, lighting systems, insulation etc. as efficient as possible.
If by chance you're building new, design for efficiency and for your local climate - if you're not familiar with passivhaus and other such standards, look into them and determine whether a 5%-10% higher construction cost is worth it for 60%-70% lower energy use and 90% lower heating/cooling energy use for the life of the house. But if you go this route use a contractor familiar with these standards or you could end up with a house that is prone to mold and poor air quality, among other things. Ditto for trying to make existing buildings really airtight and insulated.
Take advantage of energy audits your utility can provide to identify missed opportunities.
If you live in PA or other places with electric choice, choose a supplier with cost-effective renewable power. You can often find wind and solar electricity within 1 cent/kWh of the cost other suppliers charge.
Look at solar leasing companies like SolarCity, which will install panels on your roof for you, maintain them, and charge you per kWh but 80% less than the rate your normal utility charges.
Home solar installations are expensive because doing anything at small scale is more expensive per unit, but in this case there are (not yet available everywhere, but still) workarounds to that problem. This should be one of the very last items on anyone's personal energy savings and greenhouse gas reduction todo list.