Start the conversation in a slightly flirty manner. But don't try to do too much. Lest you become too flirty and their mood deteriorates.
Interesting
Make sure that your interaction with them is interesting. You have to maintain a balance between flirting and penetrating. If you ask them how your day was, it will not be interesting at all. They will not be interested in giving you information of their day.
Short
Always keep your line short. Nobody would like to read a very large text. Keep your texting creeps and sharp. That means you write less and it means more. The best would be to put a hummer in every other line.
Ask questions
Ask them funny questions. The time of your conversation will be determined by how interesting you talk to them. Ask them if you know about such and such party this weekend? Or did you watch such and such a movie? Et cetera. This will keep interested in the conversation. With emoticons, you can make conversation more interesting. For this, you can use smiley like kissing, winging, laughing etc. Many times a simple emoticon also works. Use it with an open heart to flirt.
https://www.youtube.com/watch?v=Lp1_VVgLnJY
Be in the realm
If you are flirting while texting, stay in the slightest range. Do not do this so that you send flirty lines one after the other. You have to balance the flirty line along with other things in the conversation. One advantage is that it will also send more and more text.
To tease
When someone teases girls in a flirty and humorous way, they love it. But yes, once again you will need to be within a little scope. Lest you tease them more and all the fun is left behind.
Be naughty
When the conversation starts moving forward, you get a little mischievous and bold about flirting. You can ask them what are you wearing or are you bored in bathing alone?