Make a pint of jelly and leave it in the fridge.
Take a home-made vanilla sponge the same diameter as the trifle bowl, and split into two layers.
One layer in the bowl. Drizzle 2/3 of a glass of sherry mixed with fruit juice (1:1) over the cake.
Drink the rest of the glass.
Spread blueberry jam generously over the sponge.
Place the second layer of cake on the jam. Drizzle 2/3 of a glass of sherry mixed with fruit juice (1:1) over the cake.
Drink the rest of the glass.
Keep checking the jelly. When the it has just begun to set, pour it over the cake. The trick is to keep the layers separate, not have the jelly soak into the cake. If you like, you can put tinned fruit in with the jelly. You can even lay peach slices out in a pretty whirl on the cake.
Put it all back in the fridge to set fully.
Next is custard of your choice.
And then the whipped cream. It must be real whipped cream. None of your squirty can stuff. Squirty can stuff is fine for squirting on your own individual portions, but it just won't do on a whole pudding brought to the table in all its trifly glory.
Of course the only sprinkle that can be allowed is flaked toasted almonds. 100s and 1000s have entirely the wrong texture. OK, I'll allow scraped chocolate curls.
Bon appetite!