The basic cream cheese and 'seafood' in about a 1:1 volume is a good starting point. But where to go from there? Turmeric and ground coriander, or Sriracha sauce with a healthy dash of ginger, or allspice, cinnamon and cayenne, or a jar of store bought cocktail sauce, or diced scallions and lime juice, jalapeno or chipotle if desired.
Perhaps build something starting with some tangy Greek yogurt, lemon and mint. Or a take on a hot dip, mixed with mayo and grated parmesan. Or perhaps a tapenade style with minced raw garlic, black olives and a bit of olive oil to make it spreadable.
I would have to say to make a good crab/lobster spread you should finely mince the crab and lobster chunks and add some cheddar cheese to it as well as Dill, Salt, and pepper. Add some paprika for spice. Then cook it at a low temp to melt the cheese and stir to combine all the ingredients. To finish it let it cool and add a cream cheese/sour cream mix(1:1) and combine it. sorry for not having exact measurements but I always just eye ball my stuff. And I trust you can successfully and accuratly do the same!
If you really want to impress anyone serve it in a bread bowl.