What do you actually do to achieve this?
Have a clear lead in your messages. Typically my messages will respond to a girl if she asked some kind of question, and then I'll throw the ball in her court with either a question or a logistics invite (date invite, etc). Texting should be purposeful, but yes you have the right idea with your next question:
Is it to craft sentences with proper punctuation and yet throw in some emoticons?
This is exactly correct:
1. Use proper punctuation and grammer as much as possible - the best thing to do is to look at a girl's text and match her style (if she uses a lot of punctuation, do it; if she doesn't, don't do it as much).
2. Use emoticons to convey the mood of a message. Don't overdo this.
3. Always use your texts to lead a girl towards something.
Remember that the purpose of texting isn't a date - it's to set up a date and logistics. So you should be using texting to facilitate whatever you need to in order to get her in front of you.
What is your style of texting like?
Honestly it's really simple, dumb, and boring - but I only use texting for two things - building enough comfort to invite a girl out to a date, and then logistics around the date invite. That's pretty much it (at least until we have sex, at which point it'll be more).