ETA:
@Guinan
Yay! I'll be rooting for you. It sounds like you are extremely prepared already. I would say just keep the things in mind we already discussed so you can ask about that.
Also, make sure you understand what you are paying for and that there won't be any bait and switch going on in terms of what you paid for and what you expect.
So for example, make sure you explicitly tell them what you want with the pictures to support your vision. It helps to also go with your hair down or easily accessible so the loctician can evaluate your hair in terms of thickness, length, etc. so they can also set their expectations.
So if your hair is in a style, be prepared to take it down. The loctician may not do all that for you. Same goes for your actual install appointment for when they put your starter locks in. Any extra work they have to do outside of the normal install will put them behind and they may bill you for it.
Better yet, ask them how you (mainly your hair) should present on the day you get your locks put in. I started my own locks this second time around, so I can't give you any insight into what to expect there. The other ladies might be able to chime in on that aspect.
I don't know if traditional locticians offer certain packages the way Sisterlocks consultants are trained to do, so also keep that in mind. I said all that to say, they may offer you a shampoo, condition, and then put your locks in for a set price or they may ask you to come with your hair already washed and clean and they're just doing the install part and that service alone may be considerably less.
I washed my hair prior to my SL install the way I was instructed to, and didn't put any conditioner in my hair.
I braided my hair down into plaits and my consultant asked me to take the braids out when I got to her. I'll admit, I felt some type of way that I had to do that. But I assumed she would, and that wasn't the case. I also didn't ask beforehand either.
Also, be sure you ask about the maintenance method they'll be using to maintain your new growth and that they don't stray from that. If you plan to retwist your new growth, make sure the products they use are products you approve of. Don't let them put wax or other things that are not good for locks in your hair.
If they're going to be interlocking your new growth, ask what tool they will be using. You may need to tell them what point rotation you want. If you don't know, you can ask what they recommend. They may decide for you based on your hair type and other characteristics. Or they may ask you to choose after explaining.
Make sure you get an appointment that fits when you want to start your journey. If for some reason, you aren't comfortable with an appointment that is really far out, or anything else you see or learn while you are there, keep searching. Don't feel like you have to settle.
A consultation is just that. No more, no less and no harm, no foul.
Pay them for their time, thank them for their time and leave.
Also, confirm prices before you pay for anything and make sure they match up with what you were quoted back when you booked the consultation appointment and are fair in regards to what you feel comfortable paying.
Don't put any deposits down until you are sure you want that loctician. Deposits are usually non-refundable.
Don't feel pressured to pay the deposit, either, especially if you feel like you have other stylists you want to consider. Some stylists will have specials and deals to entice you into doing that, but again, make sure it's a good fit for you first.
Lastly, make sure you are on the same page about follow up visits, how to care for your hair in between appointments, etc.
Good luck and I look forward to hearing how it went!