I am fitting a cornice around the tops and bottoms of my kitchen cabinets. Do I fabricate the whole assembly before fitting, ie glue all the mitres first, or is it better to fit each length in turn, glueing it to the last. There are four mitres on each. I am concerned that if I use a proper mitre glue, which I want to do, and I fit it piece by piece, it will be difficult to align the joints before the glue sets