I'd never consider:
o Traditionally male names used for girls
--James, Logan, David, Aidan, etc.
o Most unisex names (or recently viewed as unisex... meaning names that were viewed as male up until recently, but are now seen as being unisex or even female):
--Shannon, Morgan (though for a long time I wanted to use that one), Kelly, etc; and also the recent ones: Hayden, Jadon, Peyton, Mackenzie, etc.
o Most last names used as first names (ESPECIALLY on girls)
--Mackenzie, Hayden, Madison, Taylor, Kennedy, etc etc.
o Names that mean "son of ___" for girls
--Mackenzie ("son of Kenneth"), McKenna (also "son of Kenneth"), Madison ("son of Maud"), Addison ("son of Adam"), Emerson ("son of Emery"), etc etc.
o Trendy names
--They -ayden trend (Jadon, Caden, Aidan, Hayden, Brayden, etc)
--Made up names (Kayla, Kailey, Nevaeh [*shudders*], etc etc)
--Also includes all the previous categories.
o Names in the top 100 (preferably not even the top 500). I like my names to be unusual. Even if I like the name a lot, I wouldn't use it if it were in the top 100.
--Jacob, Michael, Joshua, Ethan, Matthew, Daniel, Christopher, Anthony, Andrew, William, etc.
--Emily, Emma, Madison, Isabella, Ava, Abigail, Olivia, Hannah, Sophia, Samantha, etc.
o Non-Celtic names... this is specifically for my kids. We prefer our children have Celtic names. I love a lot of non-Celtic names, but we wouldn't use them for our kids.
There are a few more things in my list of criteria, lol... but this should suffice for now.