I would like this thread to collect Info about the Hardware Design of Battery Powered Applications.

(All the Do's and Dont's)

So far I never really had to care about "power consumption"
as my applications have always connected to Power Supplies with almost "infinite" capacity.

Now I have got the challenge to design a battery powered "standalone" device
that has got to be "as small as possible"
and should run reliably for at least 6 months without the need to recharge/replace the battery.

I have got to run the the Board at exactly and stable 5.00 V as there are some analog sensors.

All Linear LDO's I have found so far do have a quiscent current that would flatten
a "small" Battery within that period of time.

How do you solve this kind of problem?

Again:
I'm not asking how to reduce the Systems power consumption by turning off peripherals,
the question is about the design of the power supply.