Cut the baguettes into 1/2-inch slices (so you have about 20 slices) and brush each slice on both sides with some olive oil.
Grill the bread on a grill, grill pan, or electric grill for a couple minutes on each side. Alternatively, you could bake the bread slices at 360°F (180°C) for about 10-12 minutes in the oven.
Chop the capers, dill, and spring onions.
In a bowl, mix the cream cheese, chopped capers, finely chopped spring onions, and finely chopped dill, lemon juice, lemon zest, salt, and pepper.
Spread the herb cream cheese mixture over the baguette slices.
Top with smoked salmon or lox.
Optionally, garnish the crostini with some fresh dill and serve on a board with lemon wedges/slices.