I'm right-handed, but play drums 'lefty'. I have a younger brother, totally left-handed; he plays guitar (very well...) right-handed. Whatever comes naturally, plus practise, is the thing, that's all.
All sorts of tricks concerning jack sockets; one that might be useful is to use a knitting needle, slid into the jack hole to 'fish out' the socket. Once guided out, put a nut on it and tighten it up, with fingers at first, then with a spanner, socket or, at worst, a pair of pliers, end-on. Tip: slide the knitting needle through the retaining nut before anything else, so that it's already in place when the threaded part of the jack peeps out. The hardest part is often obtaining a suitable jack socket retaining nut in the first place, though; good luck with that.