The first few times I did it I followed a recipe but can't remember what it is now - might have been from Jane's Patisserie, that's where most of my baking comes from.
But essentially, I soak slices of chocolate Swiss roll in a orange liqueur x orange juice mix, then layer in a bowl with chocolate custard layers and freshly whipped cream on top. I've put a few drops of orange essence/extract/fresh orange juice in the cream while it's whipping in the past and it's been spectacular. If I'm trying to impress people I make my own custard but this year I'm using tinned because who can go to the effort, but if you can be bothered it can be well worth it. Top it with artistically arranged terrys chocolate orange segments. I like to grate a bit of dark choc on top too for contrast/to cut through all the milk choc but I forgot to buy some this year oops.
When I was a young thing of 20 or so, my trifle was requested for many parties. A friend once had a dessert themed party just to make sure I'd bring one. Then I would skip the orange juice entirely and just soak the sponges in orange liqueur, used about half a bottle plus per trifle and it was delicious but
bleeping hell it was strong. Now im verging on late 20s and don't have the same constitution I used to I use a few measures of liqueur in fresh orange juice and it still has a kick but is much easier to eat and not feel like you're going to fall down imo
Will take pics tomorrow if I remember! It's going to be a strange Christmas this year but I have my health and I don't live alone, so I'm feeling lucky compared to a lot of folks out there