The bowl should be glass so you can see the layers. A trifle is a centrepiece and I think a large straight-sided bowl is the most dramatic choice.
We have loads of brilliant fruit at Christmas so it’s only right to plan your trifle around something seasonal and then build the flavours from there. You might choose chocolate custard and an almond cake to go with impeccable nectarines, or a dark chocolate cake splashed with kirsch to go with the season’s best cherries. The fruit can be fresh, poached, macerated, used for jelly, set in jelly, or a combination of all.