I've enjoyed prawn cocktail starters ever since I discovered the dish in 1975 (at the Minerva Greek/English restaurant in West Croydon, long since gone). Over the years, I've found (as one does) that different establishments each have their own way of preparing and presenting this starter, as for other dishes.
Some would serve it up in shiny metal dishes, some in glass, some on a plate. Some would include a slice of lemon, sometimes in a squeezer, others on the edge of the glass/dish. Some might have a small slice of cucumber and/or one of tomato. And so it went on...
My preferred style was with the tomato and cucmber slices, plus lemon to squeeze the juice of over the dressing, and cayenne pepper. This I found delicious, especially with slices of brown bread on the side.
My own experiments, here and at Chateau John before that, have included substituting king prawns (either standard or large) for the usual prawns, and sometimes paprika for the cayenne pepper. I also sometimes have a crusty white roll, warmed and still crisp, with butter (this is one of those occasions where no other spread works as well), and I have just done today – indeed, with all of those variations: large king prawns, a good mixed (crispy) salad, paprika, and a warmed crusty white roll with butter.
All of this was washed down with the classic (if unadventurous) Montpierre French Sauvignon Blanc, which happens to be ideal for this sort of meal.
In recent months I have also been trying a new (to me) technique of pouring out the first glass of white wine well in advance, and placing the filled glass in the 'fridge to chill, i.e. glass and all. It's actually rather good; so if I am sufficiently on the ball, I hope to make this a more regular practice.
Overall, even something as comparatively simple as a prawn cocktail can be made more interesting with a little experimentation, and I do recommend trying variations on such established themes.