Which combination flows better /sounds better?
[name_f]Celeste[/name_f] [name_f]Cecile[/name_f]
OR
[name_f]Cecile[/name_f] [name_f]Celeste[/name_f]
I know its not the best combo, but I [name_u]LOVE[/name_u] these 2 names so much and dont want to miss either one especially [name_f]Celeste[/name_f] 
Still… Im a bit concerned if its the worst combo ever? 
its fine if you dont like the names btw, thank you for taking your time to help me out!
I know how you feel, it was like when I was debating between [name_f]Lila[/name_f] or [name_f]Lily[/name_f] and I just felt like using both!
To answer your question, [name_f]Celeste[/name_f] [name_f]Cecile[/name_f] flows the best. However, it is a bit of a tongue twister because they both start with -ce, and if it was me, I would not use both names. But on the bright side, it’s not likely someone will call you both names at the same time, so use them if you like it that much 
I would go with [name_f]Celeste[/name_f] [name_f]Cecile[/name_f], but I agree with @calistee - either way it’s a mouthful because the names are so similar. I would go with only one, but since I’m assuming you’ll go by your first name only, it isn’t the end of the world.