Here is how I'd go about it
- write image to SD card that is exactly the same size or smaller than your target SD cards
- boot this card in a pi
- update/upgrade, and perform any other customisations you want/need
- shutdown gracefully
- add
init=/usr/lib/raspi-config/init_resize.sh
at the end of the first line in cmdline.txt
(if you used a smaller SD card in step 1
- create your new image from this SD card
Step 6 depends on your computer ... how do you do step 1? Does this process/program have a read image instead of write image function (win32disk image does)
if you use dd
it's simple
to write, it's something like
dd if=raspbian.img of=/dev/someDeviceHere [other options]
to create an image, simply swap if/of
dd of=myraspbian.img if=/dev/someDeviceHere [other options]
where [other options]
are whatever else you use on the command line