In reply to somethingelse:
> Apologies if this is daft question, can't seem to locate a definitive answer anywhere easily.
It's not a daft question but you're unlikely to get a definitive answer here either. In reality you don't need the strongest or the safest possible set-up, you need one that is simple, adequately strong and adequately safe. Peoples views differ on what's simple/adequate so their favored set-ups differ.
> I read on the link below that clove hitches have to be orientated correctly against the strong spine of the carabiner. Does this mean you should only really have one clove hitch per carabiner? Or does it simply mean that each of the clove hitches should be correctly orientated (see diagram in link) with the load running on the spine-side of the knot? If the latter then is the only limit on the number of clove hitches you can have on a carabiner down to the size of the carabiner itself?
I'd be suspicious of anything telling you you *must* do something a particular way.
One hitch per krab with the loaded strand nearest the spine is the strongest configuration for a clovehitch (itself not that strong but strong enough for what we use it for).
Load the krab further out toward the nose and you start to impose bending loads on the krab. Is that serious? For bodyweight: No. For holding a big (factor 2 say) fall? Well for starters the krab is unlikely to fail even if the rope holding the fall is clipped in sub-optimally with no other load limiting devices involved. Add in the load limiting effect of the hitches slipping and a belay plate plus a realistic human belayer... The problem is the belayer, not the rigging.
Where does that leave you? Personally I pack as many on as will sit neatly on the end bar of the krab, on a small screwgate that's maybe an 8 and a clovehitch, on a big HMS that could be 3 or more clove hitches in skinny rope. Thoughts of the krab failing don't even come into my mind.
Actually, what I usually do is tie back without any krabs because it's quick and simple. Worth learning even if it's just as a back-up plan.