Texting should always be different.
There are many good threads about text-game here, search around.
There are many on this forum with their game on lock. All age groups, all designs. For every 'type' of woman, there's a PUA who will game her.
For me - Texts are always light, random, funny, sexual or exciting. I'm her escape during the day. BUT - I make her miss me. I don't respond as much as she'd like. I throw in differentials to ensure my texts are always received later than she'd want, and are anticipated. She subliminally starts yearning for my texts (Pavlovian theory), and gets conditioned to understanding I'm a busy man. Then, when I text, it holds more weight than those from other men - until she realizes I'm the only option that gives her that.
PUAs get the concept: She's getting texts from other dudes. You're "one of the crowd" insofar as that goes... So, how do you show that you're THE one in the crowd? Be different, be the exception and be random.
I'll start a throwback text string (tapping a re-tread) with "Wanna help me rob a bank?"
I've started with "I bought new socks, and I'm wearing them today!"
Or... "Don't make me tell you what I really think of you..."
I always escalate sexually from there. I use the random's for initiating the conversation, I steer the conversation sexually thereafter. If she doesn't, I'll always have a different conversation stream I can segue into - then I'll throw out "Work calls, gotta bounce. Call/textme later...

"
Remember - a text stream is NOT a conversation - it's a shortened message. Context is removed, so keep that in mind when you send a text to begin with. Use that to your advantage. Also implanting an exit abruptly is easy - and becomes an accepted norm. It's only "rude" if you admit it's rude. If you frame it that you're busy, you prefer to meet in person, but you're into her and text her just because SHE likes it... you control it.
Never send negative texts. Always be upbeat, random, sexual - I'm vague ONLY when it serves my purpose.
My progression: Text to Sext to Phone to Fuck.... logical progression.
Search away through the discussions, there are many great references here on this forum alone without having to search all over.
Best,
RR