Chop the smoked salmon into small, bite-sized pieces, mince the red onion finely, chop the fresh dill, and drain and mince the capers. Having everything prepped ensures you can work quickly once you start building the dip. Set all prepared ingredients aside in separate bowls or on a cutting board.
In a medium bowl, combine the softened cream cheese with fresh lemon juice and sour cream, stirring until completely smooth and well combined. The cream cheese should be at room temperature to mix easily without lumps—if it's too cold, let it sit for a few minutes. I like to use a rubber spatula and work it against the side of the bowl to break down any remaining cream cheese chunks for the smoothest texture.
Gently fold the chopped salmon, minced red onion, fresh dill, and minced capers into the creamy base from Step 2 until evenly distributed. Use a gentle folding motion rather than stirring to keep the salmon pieces intact and maintain a chunky, luxurious texture. Be careful not to over-mix, as this can break down the salmon too much and make the dip mushy.
Transfer the dip to a serving bowl and refrigerate for at least 30 minutes before serving—this allows the flavors to meld together and the dip to firm up slightly for a better consistency. When ready to serve, give it a quick stir and arrange crackers or bread alongside for dipping.