Hmm. Alliteration or similar endings, I wouldn't do, personally. For any sib-set I'd want names that have similar etymologies of 'vibes', but with twins I
might choose matching / opposite meanings, or be keen that they had the same overall syllable count.
If I had to name twins right this second:
Cecily InèsTamsin Hélène
Cecily InèsElian Tomás
Leon TomásEzra Corentin
One of my absolute guilty pleasure ideas for twins is first names
Tamsin and
Tomás, because the meanings are just too perfect, plus
Tomás would be honouring for me and
Tamsin is one of my favourite girls' names ever, but it's just too much, I think. The children would hate you. So I just work one or other in, aha.
"You can have freedom, or you can have peace. But not both at once."
http://www.behindthename.com/pnl/151927