I'm afraid our process was more about what we didn't want and seeing what was left:
No initial that was already in the immediate family or a surname. So not the same initial as my name, dp's name, or either surname. I had the same initial as my grandfather who lived with us when I was a teenager and post was often addressed to t defrance (no mr/miss) so he often opened my post.
No name that was already in use by our generation of the family or friends - brothers, sisters, bils, sils, cousins.
Pronouncable by foreign friends / family (French in my case)
For girls - no girls version of boys names (eg Louisa) or anything too flowery. Actually any girls name ending in a. Our girls list was pretty short!
Something long that could be shortened if wished. DS1 now goes by 2 different shortenings neither of which occured to us when choosing the name and does not like to be called by the long version, but at least has the option when he grows up if need be.
Only one spelling - so Isabel/Isabelle/Isobel and Catherine/Katherine/Kathryn were rejected
Not in the top 50 - managed this with DS1, DS2 is in the 40s somewhere I think. My name is pretty unique in this country and I like that. But agree with pp's saying boys names need to be more traditional.
No negative associations, eg I liked Michael but DP knew someone at work who he didn't like. I imagine this is very difficult for teachers.
I think that was it!! In the end DS1's name was a character in a film I saw when pregnant. DS2's had been on the shortlist for DS1 and we hadn't had any better ideas (or none we could agree on!)