Hi Mick
I tend to make the pastes together as I don't find myself needing one without the other.
Chop up 50\50 amounts of garlic and ginger
Add to a food processor with a little water
I usually add a splash of oil, this is optional though, tends to stop it going green
Keep adding water until it there is enough for it to blend
Should keep for a couple of weeks in the fridge, iv've kept it for longer or can be frozen in an ice cube tray.
I think there is a more detailed description amongst the Bruce Edwards articles.
cK