For my Not So Berry yellow generation, I really wanted my matriarch to marry an alien. I downloaded a number of aliens from the gallery. I was using Wonderful Whims at the time too and I set her preference to aliens.
Sometimes I have used random townies, like for my scientist in the active career. She met someone at work she got on with well.
I tend to play premades mostly, so I have them fall in love and marry other premades. For example, Maikke Haas and Gunther Munch got married and had triplets.
I am not currently using Wonderful Whims, but when I did I used it only as one factor. I wanted some level of physical attraction to begin the relationship, but other things are more important. I would love it if only the attraction portion of the mod were available, but other parts of the mod annoyed me. I tried turning them off, but sometimes they persisted when I rotated to another Sim. I have been using the First Impressions mod now to get an idea of how Sims react to each other on first meeting.