I didn't. When deciding I almost flipped a coin but kept wanting it to be keep my own name which was telling me something!
So I kept it!
Reason was that I just wanted to remain as me when I married and not try to morph into a wife role. Yes, totally ridiculous, but I didn't want marriage to change my persona and keeping my name felt important.
I also didn't want to be a Mrs in paper. I use Ms if I have to and much rather it than Mrs. Although I can't see the point of a salutation in this age really. And what does my marriage status matter to my utility people?
In regards to children, they don't have my husband's name or my name. They have a sort of hybrid. When registering, the register said we can call them what we want, Mickey Mouse if we like, so we agreed on a new surname for them.
When my second was born, a different registrar caused some hassle saying it wasn't allowed and what about future generations tracing their ancestry, etc. She had a big objection to it. But as it was done on my first, their was not much she could do.
I love what we have done as a family. The children share a unique name but ours are different.
Not sure how I'd feel if I was the only one with the surname in the family.
Another idea, which we almost did, was to blend our two names on marriage to create a new shared one. Lovely idea and I've heard a few times since of couples that did it.