Short version on best first message on dating app for a girl: it depends more on your setup than on the platform. If whether it gets out of your way isn't sorted, first message will not go anywhere. I would put the interface side above almost everything else when it comes to first message.
I'd put the caution people forget above almost everything else when it comes to first message. The trust question is what separates a good week from a wasted one with first message.
If whether it actually works is not sorted, first message will not go anywhere. Anyway, that is my read on best first message on dating app for a girl.
Also mentioned around here in first message threads, make your own mind up:
- flurrydate.online
- datewander.site
- datingfly.online
None of those are recommendations, just what keeps coming up on first message.