Definitely dick pics - always a TW
I nearly always ignore but couldn't resist sending a brief message to one who had no intention of making a booking-
"That looks just like a penis, but smaller!"

  Perfect

"I'm a genuine guy..."

Genuine guys don't need to tell people they are genuine.

On the phone -

Say hi but no more
Call me babe / baby / darling / sexy, anything overly flirty that is not my working name
Asks for my location before introducing himself
Asks am I available / am I free etc
Tells me he's seen my ad and how beautiful I am (really? You can't see my face pal, I might look like a bag of rusty spanners)
Asks me how I am, how I'm doing

By text

Anything text speak in any way shape or form
Anything overly complimentary
'Hi' 
Anything abrubt, one worded, 'location', 'available' etc
Any second text that continues the initial communication, after he has received an auto text telling him clearly to PHONE ME (a text that says ok I'll ring later is fine)
Anything 'offering' me less than my rate for any reason whatsoever

This is not an exhaustive list. 

How hard can it be to follow this simple guide?

"Hi, is that xxx?"
"Yes, hello, how can I help you?"
"I would like to see you today please at xx o'clock."
"No problem, how long for please?"
"30 minutes please."
"That's fine, that's XXX amount."
"Ok no problem." At this point, perhaps one, maybe two simple reasonable questions are acceptable.
"Please confirm booking at XXX o'clock"
"I will, thank you, see you later."
"Look forward to seeing you!"

Not difficult guys, really.

In all fairness, I have seen some sizeable units who would understandably have had a struggle in certain activities due to their size.  However, TW displays are usually multi factorial and not solely the mention of their appendage making them easy to spot.

I've seen some, too.

But none of them warned me in advance.

I disagree with that .  I do 90 percent of my work by text . the last 3 days all my bookings have been done by text and I have been very busy
The only one one I spoke to today fucked me about 😂 Which is very rare for me

Yeah I used to find text guys to be TW when I used to work before I took a few years out, but this time around I had to adjust to text bookings because I find them now to be genuine a lot. I think because it used to be more a "I want to waste an escort's time so doing it via text enables me to overcome nerves/dupers delight in a phone call" and now its become more and more an acceptable form of first contact just in general.

Blokes that ring, then hang up, then text something dumb like 'hi'

Blokes that ring, then hang up, then text something dumb like 'hi'

Or worse "Hi how are you x"  ridiculous!

One fool has been texting me for a year asking if I ever come to Leeds I've already told him at least 3 times that I don't, so the other night he asked again and I just replied (very unprofessional I know but I was sick of it)  "Fuck off"  He still continued saying sorry  I've just sent his stupidity to spam now.

The annoying texters 
This is when I wish they had to pay a premium to txt us over and over again! Not just a txt from their free txt package on some throw away SIM card 

Ye because the phone numbers out there, *some* cretins think its fine to text random women at anytime of day or night because she offers sex (for money!)