Power drains

I’m writing code to work, and not paying attention to how much power it uses.  I am making a list of the things that require attention in order to save power:

1. The SPI is working in poll mode, so the processor stays awake while the bytes are being transmitted and received.
2. The SPI is operating at low speed
3. The DW is working at 100K instead of 6.8M
4. All packets have a lot of empty space in them
5. GPIOs are left with pullups/downs when processor sleeps.
6. LEDs 
7. Clock  accuracy
8. user manual p159 – 1ppm crystal for DW