I literally can't, depending on who I'm texting. When it's the guy I've liked for years now, I become so anxious over whether I'm bugging or annoying him or creeping him out (which is totally illogical) that I have to be physically restrained while a friend hits "send". I just can't do it.
Only if it's a close friend or family member, though in that case no one ever really "texts first," we just have an endless convo going.
Otherwise I NEVER text anyone first, next call anyone first, never approach them, make the first move, etc. I don't even friend people on FB or anything I keep to myself. (though maybe not on ATRL )
If I have a question to ask or have something really interesting to share, I'll send the first text and a conversation usually picks up from there.
I love texting / talking to friends, but I rarely start a text conversation because I don't want to feel like a nuisance... but if they start it, I'll continue replying until they stop sending messages (I don't like leaving people hanging). }: )