As an occasional and always very hesitant diy plumber, I've always used
traditional soldered or compression fittings in the past. I'm just
about to fit an outside tap and my local B&Q has a very patchy stock of
fittings. As a result I've bought a brass tap plus a selection of these
new fangled push fit fittings (some copper, some plastic).

I'm a bit wary of the push fit stuff - is there anything I should watch
out for? What if it leaks on test, how do I tighten it up or get it
apart again?

TIA

Steve