As someone who also builds on carpet, I agree that a wrist strap is fine as well. I built my Sandy Bridge during the winter when it was dry in the house, and I just made sure that parts were connected to something that is grounded or out of the anti-static bag only when I was ready to use them. I like PSUs that have an on-off switch (most of the non-exploding ones do) because you can use them as ground by having them plugged in but turned off.
It may be a paranoia step, but while I was installing the CPU and cooler to the motherboard, I also had the motherboard connected to ground. I did that by running an test lead (wire with alligator clips) between a USB cable connected to the motherboard to a computer PSU (actually an old AT, no 'X' power supply

) that was off.