By asking “How’d you think to…,” you are showing that you are interested in learning more about the other person – their processes of how they came up with the idea or design or strategy.
You are asking them to share more about themselves. This builds connection.
Often, this type of conversation does more for the relationship than a compliment. “That looks great” vs “How did you think of putting those two elements together?” (Ask “How” rather than praising the “What”).
The key is to be genuinely curious and interested in knowing them better.